The suicide bomber struck as the convoy passed through Kabul's eastern Yakatot neighborhood, where U.S. and NATO forces maintain complexes. Facilities operated by the Afghan National Security Forces located nearby.
Firdous Faramaz, Kabul police chief spokesman, said four Afghan civilians were killed and three wounded in the attack. Bob Purtiman, public affairs officer with the U.S. military in Kabul, said four U.S. service members received minor injuries. The one-line statement did not elaborate.
In a telephone interview, Taliban spokesman Zabihullah Mujahid took responsibility for Friday's attack on the U.S. convoy in Kabul, claiming 10 U.S. soldiers were killed. Taliban claims are often exaggerated.
Witnesses said the explosion was powerful, blowing out windows in neighboring buildings. Traffic on the streets was light because the bombing occurred on a Friday, the weekly day off. On Thursday, six people were killed when a suicide bomber blew himself up outside an Afghan army academy and training center, also in the same area but several kilometers (miles) away from Friday's explosion.
The Interior Ministry on Thursday said a soldier had noticed a suspicious person, and as he approached him the attacker detonated his explosives near the academy. The soldier's action likely saved lives.
Both the Taliban and an Islamic State affiliate have infiltrated the capital in the past. In a series of coordinated attacks by Taliban fighters late Thursday in Charchino district in southern Uruzgan province, 11 soldiers and five police were killed, said Mohammad Karim Karimi, deputy provincial council chief. Karimi said he had repeatedly requested the government in Kabul to send additional security forces to the district, which has a strong Taliban presence.
Attacks by the Taliban have continued unabated despite peace talks with the United States as well as a fresh round of talks with Afghan notables this week in the Russian capital Moscow. Following the Moscow talks, Suhail Shaheen, spokesman for the Taliban's political office in Doha, said "spectacular progress" was made on some issues, without elaborating.
The Taliban have rejected repeated demands for a cease fire, saying the fighting will continue until U.S. and NATO troops withdraw from Afghanistan. They also continue to refuse to hold direct talks with the Afghan government, calling them U.S. puppets, yet several senior government personalities, including members of a Kabul peace council attended the Moscow meeting. The Taliban have said they will meet with members of the government, but as ordinary Afghans, rather than as government representatives.
Associated Press writer Kathy Gannon in Kabul, Afghanistan contributed to this report