Protesters chained themselves to the gates of an arms factory preventing workers from starting their shift.

EDO MBM boss Paul Hills was forced to scale the fence and use wire cutters to let staff in through a hole.

About 100 employees arrived for work at the plant in Home Farm Road, Brighton, at 6am yesterday to be met with up to 20 protesters from Smash EDO - which is campaigning against the firm's manufacture of bomb release parts for British, US and Israeli forces.

Activists had encased their arms in concrete and attached themselves to the fence with bike locks three hours earlier.

Mr Hills, the managing director, stood on a car bonnet at 9am and climbed over the fence and returned with an angle grinder.

He cut a hole which staff climbed through.

Sam Hayward, of Smash EDO, said: "At this point the people locked to the fence decided to leave.

"It was successful because production was stopped for several hours, from 6am to 9.30am.

"We will not stop protesting until the factory is closed down."

Lorna Marchant was one of the campaigners locked to the gate.

She said: "There was some confrontation between staff and protesters.

"We decided to move because EDO staff were getting in through the hole in the fence."

The Smash EDO protesters have staged numerous campaigns against the US-owned company, including a rooftop protest and demonstrations across the city.

Police said they attended to prevent a breach of the peace and obstruction of the highway.

A spokesman for Sussex Police said: "Two people used tyres filled with concrete to block the two gated entrances to the premises and others chained themselves to the perimeter fence.

"A makeshift entrance was cut in the fence to allow employees access to the building."

No arrests were made.

EDO MBM, which also has a factory in Fishersgate, declined to comment.