London: A leading hospital in south London was forced to turn away sick patients and ambulances from accident and emergency after it ran out of beds.

Health campaigners warn that the system is in "meltdown" after two other hospitals were overrun with patients and there are fears of a winter bed crisis in the capital.

St George's hospital in Tooting has been on "black alert" since last Sunday because of the number of people needing treatment. For three hours on Monday night, St George's was forced to divert ambulances to nearby hospitals and it is still advising people with minor ailments to stay away from A&E (accident and emergency).

The situation raises questions over plans to turn the hospital's A&E department into a major trauma centre. It is one of only three hospitals in the capital deemed good enough to become a trauma centre, and could be treating most of London's most seriously injured patients by 2010.

A spokesman for the hospital said the problems were caused by a big rise in the number of patients coming to A&E - 14 per cent more than last year.