Striking firefighters were furious when they spotted a group of drinkers in firefighters' uniforms.

When challenged, the group claimed to be Royal Navy officers due to replace firefighters during yesterday's industrial action.

Off-duty firefighters from Preston Circus station, Brighton, feared their image was being tarnished.

They were also concerned the public would assume they were members of the fire brigade acting boisterously in the city centre.

However, Navy officers insisted their staff would never act so unprofessionally and found the four uniforms had been stolen from the Navy's temporary fire station in Dyke Road, Hove.

The phoney firefighters were spotted in the Walkabout pub in West Street, Brighton, last Friday night.

They later moved on to the nearby Event night club.

Gary Smith, Fire Brigades Union branch chairman for Preston Circus, said: "These idiots obviously thought they would improve their chances of pulling by wearing firefighter uniforms.

"They were generally larging it up and our guys who saw them were not happy with the way they were portraying the fire brigade.

"They said they were Royal Navy. But we suspected they may be lying.

"We have no argument with the Navy people. We are as upset as them that people are behaving like this and claiming to be someone they are not."

Police and the Ministry of Defence are investigating the thefts.

A Navy spokesman said: "None of our lads would have been out behaving like this - they are not that sad.

"We have been frantic this week trying to get replacement uniforms from Portsmouth."

Military firefighters were called into action 17 times in Sussex during the fire brigade's 24-hour strike which ended at 9am today.

Crews dealt with a small fire in the kitchen of a flat in Richmond Terrace, Brighton, last night, and they later tackled an electrical fire in a guest house in Grand Parade, Brighton.