Authorities in Afghanistan say up to 22 insurgents were killed Thursday night during an operation led by coalition troops.

The U.S. military says coalition and Afghan forces raided a compound in central Ghazni province, and that a number of militants were killed. Afghan police put that number at 22.

Officials also say troops found a cache of weapons, including grenades and ammunition. 

In other clashes, two Afghan policemen and two British soldiers have died in separate incidents. Afghanistan's interior ministry says a roadside bomb killed the two police officers near the southern border with Pakistan on Thursday. 

The latest British deaths were in southern Helmand province. British and U.S. forces are conducting an offensive in southern Afghanistan to try to clear out Taliban militants. Nine British troops have been killed in as many days.