Several suicide bombers targeted a NATO compound in the western city of Herat on Monday, sparking a clash with Afghan and foreign forces, a TV report and officials said.
"Several Taliban fighters are involved in the attack in the city, but I can't give more details," a senior security official said, DPA reported.
Private broadcaster Tolo said a suicide bomber detonated his vehicle outside the office of NATO's Provincial Reconstruction Team in the centre of the capital of Herat province, while several other bombers stormed the compound.
Herat is a relatively peaceful city by Afghan standards.
Afghan forces are expected to take over security responsibility from NATO troops starting in July.