Afghan and U.S.-led coalition troops say they have killed several suspected Taliban militants during an operation in southern Helmand province.

Coalition officials say violence erupted as troops searched a compound for militants associated with the Taliban and other insurgents. During the search, a gun battle erupted and several suspected militants died. A coalition statement said no civilians were killed or wounded in the fighting.

Helmand province, one of the world's top opium growing regions, has been badly affected by a renewed Taliban insurgency.

Also Tuesday, the Afghan government defended its decision to expel two top European diplomats, saying they will not be allowed to return.

The pair were forced to leave Afghanistan last week, after being accused of threatening the nation's security for holding unauthorized talks with Taliban rebels.

Some information for this report was provided by AFP and AP.