A car bomb exploded near the entrance to the military airport in Kabul early Tuesday in an apparent attack on an international convoy, killing at least three civilians, Afghan officials said. The Taliban claimed responsibility for the blast, the third major attack by insurgents in the capital in four weeks. U.S. and NATO forces said they did not yet have details on the incident or casualties, but the chief of Kabul's criminal investigation department, Abdul Ghafar Sayadzada, said three Afghan civilians were killed and six wounded. Sayadzada said he was brief by NATO forces, who said at least one international soldier was wounded. Taliban spokesman Zabiullah Mujahid claimed responsibility for the attack, and said that a suicide car bomber rammed into a NATO convoy and destroyed three Land cruisers. The early morning blast rattled windows more than a mile (1.5kilometers) away and flames continued to shoot out from burning vehicles more than an hour later as fire trucks ringed the area. Small blasts could be heard, likely from ammunition exploding inside the vehicles. A police official for the area, Rohullah, confirmed the attack and said it appeared to be against a NATO convoy. Like many Afghans, the official goes by one name. A witness said he saw the car ram into a line of SUVs. I saw three or four Landcruisers for the foreigners just infront of the gate ... then there was a car and it hit them then blew up,'' said Humayun, who watched the attack from his nearby shop.U.S. forces spokesman Lt. Col. Todd Vician confirmed an explosion south of the airport, but said he did not have details. The military airport used by U.S. and other international forces is right next to Kabul's civilian airport, but they have separate entrances. Insurgent attacks, often deadly, occur in Kabul despite tight security and blast walls. Suicide bombers have hit government buildings and gunmen have overrun ministries. In the run-up to Aug. 20 elections, a suicide attack near the main gate of NATO headquarters killed seven people and injured scores, gunmen briefly took over a bank in the city, and insurgents fired on the presidential palace on the same day that they unleashed a suicide car bombers on a NATO convoy. Late Monday, two militants fired a rocket-propelled grenade at the rear gate of Camp Phoenix outside Kabul, NATO said, but said there were no injuries to anyone inside and no damage to the base. Afghan police said the two militants were killed.