Hundreds of Afghan army troops and NATO peacekeepers in tanks were deployed around the city, as chanting protesters marched on the presidential palace and rioters smashed police guard boxes, set fire to police cars and ransacked buildings, including the compound of aid group CARE International.
Witnesses said that Afghan and U.S. troops opened fire to quell protesters, the AP reports.
An Associated Press reporter saw several demonstrators pull a man who appeared to be a Westerner from a civilian vehicle and beat him. The man escaped and ran to a line of police, who fired shots over the heads of the demonstrators.
Abdullah Fahim, a Health Ministry spokesman, said that eight bodies were brought to hospitals in Kabul and 107 more Afghans were treated for injuries. He said there were no foreigners among the wounded or dead.
President Hamid Karzai urged Afghans to stand up against rioters.
The riot was the worst in Kabul since U.S.-led forces ousted the Taliban in late 2001. It erupted in the city's northern suburbs before spreading into the city center and then to other areas frequented by foreigners, including areas near U.S. and NATO bases.
A purported Taliban spokesman, Mohammed Hanif, accused U.S. troops of firing on people and said their actions showed that "Americans consider the whole Afghan nation as their enemies."
Hanif claims to speak for the hardline militia but his links to its leadership are unclear. He phoned an AP reporter in Pakistan by satellite phone from an undisclosed location.
The unrest started after three U.S. Humvee vehicles coming into the city from the outskirts rammed into a rush-hour traffic jam, hitting several civilian cars, witnesses said.
The U.S.-led coalition said at least one person was killed and six injured in the crash, but police said at least three people were killed and 16 injured.
A Kabul police chief, Sher Shah Usafi, said another person was killed when U.S. troops fired into a crowd of stone-throwing protesters soon after the crash, according to the AP.
Col. Thomas Collins, a coalition spokesman, confirmed there was gunfire at the scene, but said coalition personnel in one military vehicle only fired over the crowd. He expressed regret for any deaths and injuries.
He said a large cargo truck in a coalition convoy had suffered a mechanical failure and hit as many as 12 civilian vehicles at a busy intersection. He said the coalition was conducting a full investigation.
"This was a tragic incident and we deeply regret any deaths or injuries resulting from this incident," Collins in a statement. "We will determine the facts regarding the incident and cooperate fully with Afghan authorities."
Afghans often complain about what they call the aggressive driving tactics of the U.S. military. Convoys often pass through crowded areas at high speed and sometimes disregard road rules. The U.S. military says such tactics are necessary to protect the troops from attack.
kill," one protester in his late 20s, Gulam Ghaus, said near where rioters burned a police post.
Associated Press Television footage showed hundreds of angry young men hurling rocks at what appeared to be three U.S. military trucks and three dun-colored Humvees as they sped from the area after the crash, their windscreens cracked by the stones. A machine gun mounted on one of the Humvees fired into the air over the crowd as the vehicle sped away.