KABUL // A suicide car bomber struck a US military convoy passing through a crowded market in eastern Afghanistan today, killing at least 20 civilians and a US soldier and wounding an additional 74 civilians, officials said. Separately, two British troops were killed yesterday in an explosion in southern Afghanistan, Britain's defence ministry said in a statement. Their vehicle was struck by an explosive while they were on a patrol with Afghan security forces. The suicide attack in the east happened in Bati Kot district of Nangarhar province, said Lt Cmdr Walter Matthews, a US military spokesman. No one took responsibility for the bombing, but Taliban militants regularly use suicide attackers and car bombs in their assaults against US, Afghan and other foreign troops in the country, although civilians are the most frequent victims in such attacks. At least 20 civilians were killed in today's blast, which also killed a US soldier, Lt Cmdr Matthews said. Seventy-four civilians were wounded, said Ajmal Pardes, a provincial health official. The bomber struck the convoy near a crowded livestock market, where people were trading sheep, cows, goats and other animals, said Ghafoor Khan, the spokesman for the provincial police chief. Hours after the attack, charred and twisted remains of cars smouldered on the tree-lined street that is also Afghanistan's main road to the Pakistan border at Torkham. An Associated Press photographer said that an American military vehicle, two civilian vehicles and two rickshaws were destroyed. The wounded civilians were transported to at least three hospitals in the provincial capital of Jalalabad, Mr Khan said. The United Nations condemned the bombing, which it said, "has inflicted enormous suffering in an otherwise peaceful community." More than 5,400 people, including nearly 1,000 civilians, have died in insurgency-related violence this year in Afghanistan, according to a tally compiled by The Associated Press based on figures provided by Afghan and international officials. The US soldier's death brings the number of US troops killed in Afghanistan this year to at least 148, the highest annual tally of troop deaths since the US-led invasion in 2001. There were 111 US military deaths in Afghanistan in all of 2007. The attack in Nangarhar follows a truck bomb blast yesterday in southern Afghanistan, which killed six people and wounded 42. The blast in Kandahar city, the Taliban's former stronghold, came as the provincial council was hearing constituent complaints. Two members of the provincial council were wounded in the attack, said Kandahar Gov Rahmatullah Raufi. *AP