(Updates nationalities of reporter, NATO casualty) By Terry Friel KABUL, March 6 (Reuters) - NATO began its spring offensive against the Taliban on Tuesday, launching its biggest attacks since the 2001 war on Taliban rebels and Afghan drug lords. Operation Achilles, which will involve 4,500 NATO and 1,000 Afghan troops, began around dawn in southern Helmand province, the poppy-growing heartland of the world's top opium producer. At the same time, the Taliban said they had captured a reporter spying for British troops, and hundreds of Afghans protested over the killing of civilians by U.S. troops. "We consider this a major operation and I do not think you would be wrong if you were to characterise it as the start of ISAF's major operations for 2007," Colonel Tom Collins, spokesman for NATO's International Security Assistance Force (ISAF), told reporters in Kabul. The Taliban overran the key Helmand town of Musa Qala a month ago, ending a controversial truce, but the alliance says the main aim of Achilles is to allow reconstruction. "It signifies the beginning of a planned offensive to bring security to northern Helmand and set the conditions for meaningful development that will fundamentally improve the quality of life for Afghans in the area," ISAF southern command chief Major-General Ton van Loon said. BLOODY YEAR The open-ended operation is aimed largely at allowing the repair and expansion of the Kajaki dam hydroelectric plant. "Operations will focus on improving security in areas where Taliban extremists, narco-traffickers and other elements are trying to destabilise the government," van Loon said. A British Royal Marine was killed in combat near the dam, the Defence Ministry said in London. More than 4,000 people died in fighting last year, the bloodiest since U.S.-led forces ousted the Taliban in 2001. Hundreds of people protested in the eastern city of Jalalabad, near Pakistan, over the killing of several civilians by U.S. troops on Sunday. At least 2,000 people blocked the highway between the city and Kabul, a major trade route to Pakistan, chanting "Death to Americans!", witnesses said. They demanded strict action by the government against the Marines responsible, who opened fire after their convoy was attacked by a suicide bomber. Officials say at least 10 civilians were killed and the New York-based Human Rights Watch says between eight and 16 died. The U.S. military said that 16 people died in the suicide attack and in shooting after militants opened fire. "Suicide bombers in Afghanistan regularly pose as civilians, but that doesn't give coalition forces carte blanche to respond with indiscriminate fire," New York-based Human Rights Watch's Asia director, Brad Adams, said in a statement. "The fact that the insurgents violate the laws of war doesn't absolve the U.S. and its allies of the need to observe them." The Afghan government has launched an inquiry, but previous such investigations by the government, NATO and U.S. forces have only confirmed initial witness accounts. On Monday, NATO forces also killed nine civilians with a 2,000 pound bomb near Kabul after a post was attacked. "We didn't know who was in that building, but we saw fighters move into that area who were legitimate targets," Collins said. "The building was struck and, as we all know, unfortunately civilians were killed." Analysts say civilian deaths undermine support for foreign troops in a country where most of the population sees almost no reconstruction and development to lift living standards. The Taliban dismissed Operation Achilles as routine and said NATO could not sustain a ground battle in Helmand. "They will resort to bombing that will kill innocent people," spokesman Qari Mohammad Yousuf said by phone from a secret location. He said the Taliban had captured an Italian reporter spying for British troops and two Afghan companions in the province. "He was pretending to be a journalist, but when we investigated we found he's working for the British troops," he said. Italy's La Repubblica said it had lost contact with reporter Daniele Mastrogiacomo in the area since Sunday.
