A suicide bomber rammed his car into a US military convoy as it was passing through a crowded market in eastern Afghanistan on Thursday, killing at least 20 civilians and an American soldier, officials said. The attack outside Jalalabad, the capital of the eastern Nangarhar province, also wounded 74 civilians, said Ajmal Pardes, a provincial health official. Separately, an explosion in southern Afghanistan on Wednesday killed two NATO soldiers, the military alliance said in a statement, without dislcosing the soldiers nationalities. The bomber struck the convoy near a crowded market in the Bati Kot district, where people were trading sheep, cows, goats and other animals, said Ghafoor Khan, the spokesman for the provincial police chief. Lt. Cmdr. Walter Matthews, a US military spokesman, said at least 20 civilians and a US soldier were killed. The soldier's death brings the number of US troops killed in Afghanistan to at least 148, the highest number of troop deaths per year since the US-led invasion in 2001. There were 111 US military deaths in Afghanistan in the whole of 2007. An Associated Press photographer said that an American military vehicle, two civilian vehicles and two rickshaws were destroyed in Thursday's blast. Taliban militants regularly use suicide attackers and car bombs in their assaults against US, Afghan and other foreign troops in the country. More than 5,400 people, of whom nearly 1,000 civilians, have died in insurgency related violence this year, according to a tally compiled by the Associated Press based on figures provided by Afghan and international officials. On Wednesday, a suicide bomber driving a tanker truck hauling oil detonated his explosives outside an Afghan government office during a provincial council meeting in the southern city of Kandahar, killing six people and wounded 42, officials said. The blast in 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's Gov. Rahmatullah Raufi. The explosion ripped through the council office, flattened five nearby homes and damaged the offices of the country's intelligence service. It left a crater some 15 feet into the ground. Raufi blamed Taliban militants for the attack.