An Afghan policeman shot and killed five British soldiers after ambushing them at a police checkpoint in Helmand province and fled the scene, officials said.

The incident occurred Tuesday, Britain's Daily Telegraph reported.

"It's our understanding that one individual Afghan national policeman, possibly in conjunction with another, went rogue," a British Defense Ministry spokesman said. The spokesman said he fired without warning "before anyone could respond."

The Defense Ministry said a search was under way for the "rogue" policeman, whose motives were unclear. There were suggestions he might have had a dispute with his commander.

The BBC quoted a spokesman for the British Task Force in Helmand that three of the soldiers were from the Grenadier Guards and the other two from the Royal Military Police.

The five had been mentoring and living with Afghan police in a compound in the province's Nad Ali district, the report said. The attacker opened fire, injuring several other troops, before fleeing.

The Telegraph report said two Afghan policemen also were believed to have died in the shooting.

It was unclear if the attacker was a Taliban, whose members are believed to have infiltrated Afghan security institutions.