STAFF at Darwen's M65 services had to barricade themselves behind closed doors during a "nightmare" evening of trouble.

Gangs of youths, who have been causing trouble on the site for months, forced staff and a security guard to take the drastic action.

A 16-year-old boy has been arrested on suspicion of committing a public order offence and police are searching for another, aged 15, after the incident.

Extra police patrols have monitored the youths' behaviour during weekends but problems have now increased on weekday evenings.

Virginia Lee, assistant manager at Le Petit Four cafe in the motorway services complex, said the youths "caused mayhem" on Tuesday and had got out of hand.

She said: "They went on the rampage from McDonalds right through to Somerfield and wanted to fight the poor security guard. They were trying to headbutt him, so he ran into Somerfield and they had to put the metal shutters down in defence.

"Unfortunately it was a bit slow and they dived underneath it and carried on trying to fight him inside.

"The girl I was working with and I had to go in to the back room and lock the door behind us. I had been cashing up and they tried to come behind the counter so we just grabbed the money and ran out. We could hear all the noise through the door.

"They were throwing bins and seats around. It was the worst night yet. It is as bad during the week as it is at the weekend."

A Somerfield spokesman said:"We can confirm an incident involving a security guard.

"The guard waited at the Somerfield store until police arrived at the precinct, during which time the store's doors were monitored by staff.

"The security guard was not employed by Somerfield."

Sergeant Mark Thackeray-Scott of Darwen police said: "We have been working with the staff at the services and taking action at weekends but unfortunately it has now moved into midweek.

"We will be looking to increase patrols in the area throughout the week now. The staff know who the troublemakers are and they have been banned from the premises.