The main swimming pool at York's Barbican Centre may be shut for up to a month after a piece of metal plunged from its roof.

Shocked swimmers were evacuated from the pool when a piece of metal bracket around six to eight inches long fell into the water.

Investigators called in afterwards found more debris had fallen, it was revealed today.

No one was hurt in the incident, but a structural survey revealed stray nuts had fallen from the roof.

A "better safe than sorry" policy will be adopted before the facility reopens.

A spokesman for the council said it was unlikely that the emergency repairs will form part of the general repair programme outlined for the pool's long-term future.

Following a massive public outcry channelled through the Evening Press Save Our Swim campaign, York's swimmers demanded that the council kept the city's threatened pools open.

Currently the authority is pricing up the cost of maintaining the Barbican, which could run to £2.2 million.

But on the more urgent situation, leisure chief Alan Jones said: "We don't know the exact time scale we're working with, but it's looking like a couple of weeks or a month or so.

"We've carried out a structural survey of the roof and several problems were found. While looking around we found some nuts that come from the ceiling.

"Fortunately no one was injured when this piece of metal fell.

"Now I'm waiting for a report to tell me what the next steps are, and we are aiming to open the pool as soon as possible, but we may need to carry out some repairs."

Groups which use the pool and schools that hold swimming sessions there were informed yesterday of the closure.

Total Leisure Management, which runs the Barbican complex for the council, has been making efforts to find alternative arrangements for swimming sessions.

However, the training pool and Total Leisure fitness suite in the Barbican centre remain open as usual.

A spokesman for the City of York Council said: "Obviously, we are sorry for the inconvenience caused by the closure but we feel this precautionary measure is the right one until the roof can be properly and fully inspected.

Save Our Swim campaigner Dorothy Nicholson, chairman of the Barbican Action Group, said of the metal chunk incident: "This reflects that the pool has been allowed to degenerate. Attendance has been in decline since news of the pool's condition was publicised.

"But what the people who voted to keep the pools need to do now is get bums back on seats by spreading the word about how essential the service is."