Fire chiefs have warned against a repeat of last year's increase in 999 calls from people locked out of their houses after losing their keys during festive celebrations.

Such calls have cost taxpayers nearly £10m over the past four years in London alone, according to the capital's brigade, which has attended more than 28,000 such call-outs since 2009.

Firefighters in London attended almost 7,000 "locked out" calls in 2012/13, slightly up on the previous year, and officers fear the number could rise again. The brigade said it had dealt in recent years with calls from people locked in toilets, offices, car parks, shops, and even in cemeteries.

Belfast Telegraph