Rebels attacked a US military medical team as it was helping villagers in the same region of eastern Afghanistan where a US airstrike that killed up to 17 civilians sparked sharp criticism from the government.

A gunman has shot at a guard tower in the US military headquarters for Afghanistan hours before a memorial for the anniversary of the September 11 attacks.

Hundreds of weary US soldiers descended from the Afghan mountains after a gruelling eight-day battle against enemy holdouts. US bombers pounded the caves where the remaining fighters were hiding.