Tens of thousands have been killed in a quarter century of bloodshed between Sri Lankan security forces and Tamil rebels fighting for a separate homeland.

The military declared victory over the rebels in May 2009, ending Asia's longest war of modern times and bringing the island nation under government control for the first time since 1983.

More than 70,000 have been killed and more than one million uprooted during the civil war, according to the Internal Displacement Monitoring Centre.

The violence has its roots in ethnic divisions between the mostly Buddhist Sinhalese majority and the mainly Hindu Tamil minority, who say they have suffered decades of discrimination at the hands of the politically and economically dominant Sinhalese. Tamils comprise 18 percent of the population and Sinhalese three-quarters. There is also a small Muslim minority.

The growth of Sinhalese nationalism in the decades after Sri Lanka's independence from Britain in 1948 alienated many Tamils, eventually spurring calls for a separate homeland or "Eelam" in the north and east of the country. The biggest of the rebel groups to emerge was the Liberation Tigers of Tamil Eelam (LTTE), founded in 1976.

War broke out in 1983 when the Tigers ambushed and killed an army patrol, sparking anti-Tamil riots. Hundreds of Tamils were killed and tens of thousands forced to flee their homes.

The conflict saw massacres, abductions and torture by both sides and thousands of child soldiers were recruited by the rebels. About 1 million landmines were planted by the Tigers and the army.

India tried to intervene but ended up regretting it. In 1987 the Sri Lankan and Indian governments signed a pact giving limited autonomy to Tamil majority areas in the north and east. India sent peacekeepers to guarantee the agreement and disarm the rebels.

But widespread opposition to their presence and fighting with the Tigers led India to pull out, the last troops leaving in 1990. A year later, Indian Prime Minister Rajiv Gandhi was killed by a suspected Tamil Tiger woman suicide bomber.

The rebels were also blamed for the assassination of Sri Lankan President Ranasinghe Premadasa in 1993. Peace talks opened in 1994 after President Chandrika Kumaratunga came to power, but collapsed shortly afterwards.

The late 1990s were marked by aerial bombings, suicide bombings, the killing of both Sinhala and Tamil civilians, attacks on economic targets and face-to-face battles between government and rebel forces. Tamil bombers targeted Sri Lanka's financial institutions, its holiest Buddhist site, the international airport and politicians. Kumaratunga narrowly escaped an assassination attempt in 1999, losing an eye.

Throughout the war the Tigers were lead by Vellupillai Prabhakaran, who was famous for ordering his fighters to take cyanide if they were caught. The Tigers ran a de-facto state in 15,000 sq km in the north and east of the country, operating from a self-declared capital, Kilinochchi, in the northern Wanni or Vanni region. They had a quasi-government, their own flag, police, banks, courts and defence units including a naval wing, the Sea Tigers, as well as a rudimentary air force. The Air Tigers surprised the world with their first bombing raid in March 2007. Security experts believe the Tigers may have been the only insurgent group to operate its own air force.

Prabhakaran is thought to have been killed by Sri Lankan troops in the final days of the fighting.

The Sept. 11, 2001 attacks in the United States and the election of a new Sri Lankan prime minister, Ranil Wickremesinghe, provided the impetus for peace talks. The Tigers were keen to shed the "terrorist" label given to them by members of the international community.

A ceasefire was agreed in 2002 and the rebels dropped their demand for an independent state, settling for regional autonomy. But they withdrew from Norwegian-brokered peace talks a year later, saying not enough was being done to improve conditions for Tamils.

The island started sliding back into civil war at the end of 2005. The Tigers' strongholds began to fall in 2007 when government troops captured the east of the country. The government formally scrapped the truce in January 2008, accusing the rebels of using it to re-arm. Fighting escalated that year, with the government capturing swathes of Tiger territory in the north before seizing Kilinochchi in early 2009.

By February, troops had cornered the Tigers in a small patch of land in the northeast, along with an estimated 250,000 civilians. The majority escaped before the end of the war and are now housed in government-run camps. But tens of thousands were still trapped in the last weeks of fighting.

More than 6,000 civilians have been killed and around 14,000 injured since the end of January, according to figures cited by the United Nations, but no one knows for sure because few outside observers were allowed in the war zone.

The Tigers were accused of forcing trapped civilians to fight, using them as human shields and shooting people who tried to escape - allegations they denied. The U.N. Security Council also voiced grave concern over reports of heavy military shelling. Sri Lanka insisted its troops were only using small arms.

Attempts to turn the 2002 truce into a more permanent peace were stymied by internal divisions on both sides. After the ceasefire Kumaratunga fell out with her government over the peace process. Meanwhile, an eastern Tiger commander known as Colonel Karuna Amman split from the rebel movement in 2004 and took his fighters to the government side, establishing his own group, the Tamil Makkal Viduthalai Pulikal (TMVP).

Tensions rose after Mahinda Rajapaksa won presidential elections in late 2005 and promised to take a hard line with the Tigers.

The rebels pulled out of peace talks indefinitely the following April, and in July 2006 the military began advancing on rebel-held territory in the east. International monitors blamed both sides for a series of gross violations of the truce as fighting intensified.

In August 2006, 17 local staff of aid group Action Contre La Faim were massacred. Sri Lankan rights activists blamed local security forces for the execution-style killings and accused the government of an outright cover-up. The government denied this.

The situation deteriorated in 2006 when Nadarajah Raviraj, a prominent member of parliament from the rebel-endorsed Tamil National Alliance, was shot dead in Colombo.

The Tigers subsequently renewed their demands for all-out independence as opposed to the separate Tamil homeland they had previously campaigned for. The government responded by reimposing the Prevention of Terrorism Act, giving police and security forces wider powers of arrest.

Fighting became focused in the north in 2007 after troops drove the Tigers from their bastions in the east. Many analysts say TMVP's Karuna is one of the chief reasons for the military's success in the east, with his fighters helping the army seize rebel-held territory.

Karuna, who was one of Tamil Tiger leader Prabhakaran's closest deputies for two decades, is now a non-cabinet member in Rajapaksa's government. Rights groups want to see him stand trial for alleged war crimes stemming from his years as a Tiger commander.

Hundreds of thousands of Sri Lankans were uprooted in the first two decades of conflict and another 200,000 fled to southern India. At the height of the fighting for Jaffna in 1995, just 400 of the original population of 140,000 remained in the city.

By late 2003 many internally displaced people (IDPs) had returned to their battered towns and villages. However, in December 2004 the tsunami uprooted hundreds of thousands more Sri Lankans, compounding the crisis.

A deal proposed by then President Kumaratunga to share $3 billion of international tsunami aid ended up in limbo after the supreme court ruled it unconstitutional. The Tigers accused the government of deliberately neglecting Tamils who they said made up two-thirds of those affected by the tsunami.

The escalating war hamstrung post-tsunami rebuilding in the east and halted it in parts of the north, where materials such as cement and steel rods dried up because of a government ban. Thousands of families ended up living in temporary shelters made from corrugated metal sheeting with palm roofs. The fighting forced many aid agencies to shelve or abandon tsunami projects in rebel-held areas.

The civil war has also laid to waste large tracts of agricultural land, which has made malnutrition a problem.

Most of those who fled the war zone during the final months of fighting in 2009 are crammed into camps in the town of Vavuniya, to the southwest of the war zone.

The displaced are not allowed to leave the camps. The government says this is a temporary measure to allow it to weed out Tiger infiltrators. Aid agencies are pressing the government to identify new sites for camps with more resources.

The Tamil Tigers relied heavily on child soldiers during the war, using some as young as nine. The United Nations children's agency (UNICEF) says Karuna's faction and the government also used child soldiers.

Human Rights Watch says the Tigers used children as fighters, spies and even suicide bombers. Around a third of underage recruits in 2006 were girls, according to UNICEF.

The Coalition to Stop the Use of Child Soldiers says the Tigers are known to have recruited well over 6,000 children between January 2002 and September 2007. But UNICEF estimates the real figure is much higher.

Rights groups also accused Karuna's fighters of abducting many children to boost their strength after they split from the Tamil Tigers in 2004.

One girl recruited by the Tigers when she was 14 told Human Rights Watch how rebels would sometimes kill those who tried to escape.

"If you do it twice, they shoot you. In my wing, if someone escaped the whole group was lined up to watch them get beaten. If the person dies, they don't tell you, but we know it happens," she said.

Children were recruited at temple festivals, at school and on the way to school. Some were abducted but others signed up themselves, sometimes to escape poverty.

Another 13-year-old girl told Human Rights Watch: "We did target shooting. If we didn't shoot at the correct target, then we were punished. We had training on war tactics: if there is an army camp, how to approach, kill, plan the attack."

Sri Lanka made recruitment of under-18s an offence in early 2006.

After a quarter century of conflict, landmines and unexploded ordnance (UXO) pose a serious impediment to resettling families and rebuilding their shattered villages.

Thousands of people have been killed or injured by the mines which are planted on jungle tracks and around plantations, wells, highways and villages in the north and east.

Government officials estimate both sides laid 1.5 million mines between them. The United Nations Development Programme (UNDP) puts the figure at 1 million. Only a fraction have been cleared.

Some mines are homemade devices fashioned by the Tigers, but most are commercially purchased mines made in Pakistan, China or Italy.

Sri Lanka has not joined the international Mine Ban Treaty.

Reports of casualties dropped dramatically in 2007. There were 34 casualties down from 64 in 2006 - six killed and 28 injured, according to the Landmine Monitor report on Sri Lanka. But it says casualties are probably under-reported because of a lack of access to mine-affected areas. And the figures do not include casualties from claymore mines or improvised explosive devices set off by remote control.

The Tigers have been blamed for claymore mine attacks on troops since late 2005, but deny responsibility. Claymores are blocks of plastic explosive which send ball bearings and shrapnel flying out when set off. Another type of device is the bounding fragmentation mine, which springs out of the ground when stepped on before exploding mid-air.

After the tsunami, some land previously classified as low priority for demining, especially on the northern Jaffna peninsula, was reclassified as high priority because of the urgent need to rehouse survivors.

International aid agencies such as Norwegian People's Aid and Mines Advisory Group employ farmers and ex-fighters as local deminers who earn relatively good wages for the region.