KABUL — A suicide car bomber targeted a U.S. base in Kabul today, wounding six Afghans and eight Americans hours after gunmen killed four policemen in southern Afghanistan.

The car bombing was the latest attack to hit Kabul, coming just over a week after a team of Taliban gunmen and suicide bombers staged an assault that paralyzed the city and left 12 people dead. The violence has underscored fears that militants would try to stage attacks ahead of a key international conference on Afghanistan to be held Thursday in London.

The bomber detonated a minivan packed with explosives near Camp Phoenix, an American base inside Kabul, wounding at least six Afghan civilians, said Jamil Jumbish, the head of Afghanistan's criminal investigation unit.

The Taliban claimed responsibility for the attack and said it was targeting an international military convoy, according to a text message to The Associated Press from a phone number commonly used by the militant group.

NATO forces confirmed a car bomb struck outside the main gate of Camp Phoenix, saying it was aimed at a civilian convoy that was entering the controlled checkpoint.

Eight Americans suffered minor injuries, according to a NATO official, who released the information ahead of a formal announcement. He did not say if they were troops or civilians.