Afghan officials say Taliban militants have killed at least seven local guards in an attack on a convoy carrying goods for international forces.

A spokesman for the governor of western Farah province said insurgents destroyed at least nine trucks in Thursday's raid. Afghan police arrived at the scene to intervene.

The Associated Press quoted the provincial spokesman as saying no foreign troops were involved in the attack.

While the Taliban did not immediate claim responsibility for the assault, attacks on NATO convoys have been a major tactic in the militant's 10-year-long insurgency.

The major land routes for NATO supplies to landlocked Afghanistan also go through Pakistan, where militants there frequently target the trucks.