KABUL, Afghanistan (CNN) -- A suicide bomber rammed his sedan into a convoy carrying U.S. troops near the Kabul airport Thursday, killing at least six civilians and wounding 18 others, authorities said.
An Afghan security guard stands near damaged vehicles at the site of the suicide attack.
Four American troops who were part of the convoy suffered "scratches," in the explosion, said Lt. Col. David Johnson, a spokesman for U.S. forces.
The attack occurred near a bus stop during the morning rush hour, said Kabul Police Chief Salim Asas.
In recent months, Afghanistan has seen a surge in deadly attacks targeting police officials and American and coalition forces.
In January, two suicide bombers and several gunmen in police uniforms attacked a luxury hotel in Kabul. A Norwegian journalist was killed, along with at least seven other people, in the brazen attack on Serena Hotel. Norway's foreign minister, Jonas Gahr Stoere, was in the hotel at the time and escaped unhurt.
Afghan officials blame the attacks on the Taliban, the Muslim militia that once ruled most of Afghanistan before the United States invaded the country, routed them and installed a new government six and a half years ago.
Last month the U.S. Director of National Intelligence Mike McConnell said a resurgent Taliban has regained control of between 10 and 11 percent of Afghanistan.
Meanwhile, U.S.-led coalition troops in southern Afghanistan killed nearly a dozen militants on Tuesday during a raid targeting the Taliban, the coalition command said in a Thursday news release.
The incident took place in Helmand province, where troops and militants have been squaring off for months. Troops had been searching compounds in the Garmser District when militants wielding small arms fired at them. Troops then fired back at them.
Troops later arrested two people and found "opium processing rooms, various types of explosives, a number of AK-47s, machine guns and ammunition" in the area. E-mail to a friend
Journalist Farhad Peikar contributed to this report