The Royal Infirmary, General and Glenfield hospitals are all being put on amber alert because of the bug.

Patients who are suffering from the illness are not being allowed home until the bug has cleared, which means beds are not being made available.

Anne MacGregor, spokesman for the Leicestershire University Hospitals Trust, says this time of year is especially bad for stomach bugs.

Long queues

"We are asking people with injuries or a flu that is not that serious, to stay away from accident and emergency," Ms MacGregor said.

The best measure is to stay at home and drink plenty of fluids, as accident and emergency cannot help you, she added.

Ms MacGregor explained there was a long-standing problem with bed shortages in the county because of funding problems.

The current crisis has been further compounded by a large number of patients with respiratory problems.

The virulent bug has caused long queues at the accident and emergency units at the three hospitals.