By Sayed Salahuddin and Terry Friel KABUL, Feb 20 (Reuters) - Afghanistan vowed on Tuesday to punish those responsible for war crimes over three decades of fighting, rejecting parliament's move to grant a blanket amnesty, including to its own members and fugitive Taliban leaders. "We have our international responsibilities," Foreign Minister Rangin Dadfar Spanta told Reuters in an interview. "Under international law ... crimes against humanity, systematic violence against human rights is not a matter for amnesty." International rights groups say that punishing those guilty of war crimes is essential to bringing peace to a country that last year suffered its bloodiest year since the Taliban were ousted from power in 2001. Parliament, which includes former Mujahideen (holy warrior) leaders, ex-senior communists and former Taliban, voted three weeks ago to grant an amnesty to all Afghans, including fugitive Taliban leader Mullah Mohammad Omar and MPs accused of abuses. The move, yet to be made law, sparked a walkout by some parliamentarians and condemnation from the United Nations. "They are letting people who committed atrocities hold onto power," U.N. High Commissioner for Human Rights Louise Arbor said. "An amnesty is permanent, there is no going back on it." WAR CRIMINALS REWARDED - RIGHTS GROUP New York-based Human Rights Watch accuses President Hamid Karzai and his foreign allies of wrongly trying to bring war criminals into government as a way of ensuring stability. "For the past five years, the Afghan government, the United Nations and the international community, led by the United States, have pursued a counter-productive policy of relying on war criminals, human rights abusers and drug-traffickers instead of prosecuting them," it said in a recent report. "Karzai mistakenly tried to bring all political forces under his umbrella, while the U.S. worked with many such individuals as part of its 'war on terror'." MPs argue the rights group is biased against the Mujahideen who granted an amnesty to communists after taking power in 1992. More than 1 million Afghans died in a decade of war between Soviet-backed communists and Western-funded Mujahideen groups. Afghanistan has no formal political opposition and Karzai has included former communists, Mujahideen and tribal leaders in his administration in a bid to forge a united rule. But five years after U.S.-led forces toppled the Taliban's strict Islamist government for refusing to hand over Osama bin Laden in the wake of Sept. 11, fighting in the country is intense and both sides warn of a bloody spring offensive. More than 4,000 people died last year in fighting. There was also a dramatic jump in suicide bombings, a tactic increasingly used as insurgents copy operations in Iraq, and both the Taliban and NATO commanders are warning of a further increase this year. The Taliban have been boosted by the slow pace of reconstruction, the failure to establish a non-drugs economy that offers real jobs in the world's biggest opium producer and safe havens across the lawless and porous border in Pakistan. Spanta said al Qaeda had "resources" in Pakistan and worked closely with the Taliban, and he urged Islamabad to do more to stop cross-border infiltrations. "We work on more cooperation and I hope we receive that," he said. Pakistan denies Afghan charges it still supports its one-time protege, the Taliban, and says the rebels are bolstered by the failures of the Kabul government. Afghanistan's Western allies say the Taliban shelters and trains in Pakistan and more needs to be done on both sides of the border to quash the insurgency. Spanta said al Qaeda remained active and he believed bin Laden was alive despite his long public silence. "I have not heard anything to the contrary yet," he said. "The al Qaeda leadership is active and enjoys certain support beyond Afghanistan's borders."