THE number of children at a North-East nursery affected by a food bug has risen to nine, health officials confirmed.

An investigation was launched last month after four regular attenders at Bishop Auckland College Nursery, County Durham, became ill.

Tests found the salmonella infection, which occurs through contaminated food or close contact with an infected person or animal.

A statement from the Durham Dales Primary Care Trust said: "A team from the trust, environmental health officers from Wear Valley District Council and staff from the Health Protection Agency are continuing to work together to investigate nine cases of salmonella infection in the local area.

"The investigation into cases of salmonella infection, as always, is broad and includes exploring possible links between cases.

"Attendance at the Bishop Auckland College children's nursery is one known link."

He said the cause of the infection was unclear and that investigations continued, while measures have been taken to reduce the risk of the infection spreading.