MILITARY investigators were conducting a probe last night after four high-powered rifles were stolen from a North-East Army barracks.

The weapons went missing from Catterick, in North Yorkshire, over the weekend.

It is feared they could have been stolen to order for use by terrorists or criminal gangs.

Sources said military police believed the theft was an inside job. Civilian police have been informed and a nationwide hunt for the guns is under way.

Detectives from the Army's Special Investigations Branch ordered an immediate "lockdown" when it was found the weapons were missing on Sunday.

Troops were barred from leaving the base for 24 hours, and sniffer dogs were brought in to search the barracks.

The stolen Light Support Weapons, which take standard 5.56mm ammunition, were in the armoury at Catterick's Bourlon Barracks.

The guns can be mounted on tripods and are accurate up to a range of one kilometre.

They are a modified version of the standard SA80 infantry rifle, which is accurate to 400 metres. The modified weapons have a longer barrel to provide covering and support fire during assaults.

The guns belonged to the 1st Battalion, the King's Regiment, which recently served in Iraq.

The soldiers are recruited from the Liverpool and Manchester area.

The theft has prompted residents and community leaders to raise doubts about security at the barracks.

Lynn Miller, a district councillor for Catterick, said: "As a councillor, I am obviously very concerned, especially with the increased risk of terrorism we currently face.

"I am always surprised Catterick has never been targeted by terrorists."

Caron Henley, 41, of Peppermint Drive, Colburn, said: "I do not think security is very good at the camp.

"I think it is very easy for a civilian to just walk into the barracks."

An Army spokesman said: "We can confirm the disappearance of the four weapons from the armoury at the home of the 1st Battalion, the King's Regiment.

"It is being investigated by the Royal Military Police."

The garrison is facing calls from grieving relatives for a public inquiry into the deaths of 14 soldiers since 1997.

The base, which is the biggest in Europe, was visited on Tuesday by MPs from the Defence Select Committee.

The politicians questioned soldiers as part of a national inquiry into the care of recruits, prompted by the deaths of four soldiers at Deepcut, Surrey, including Private Geoff Gray, of Seaham, County Durham.