Twelve children in County Armagh have been infected with the E.coli bug, the Public Health Agency (PHA) has confirmed.

Seven who attend the Holly House nursery in Dollingstown were infected with the potentially dangerous 0157 strain of the bacteria.

The PHA said a further five cases were identified after screening. None of the children are seriously ill.

Holly House has been temporarily closed until the source is identified.

A PHA official said tests at the site gave no evidence to suggest that the nursery was the cause of the outbreak.

"We greatly appreciate the response of parents which has been overwhelmingly supportive," the spokeswoman added.

"We are now working towards reopening the nursery which we expect to be during the course of this week."

The PHA is working with Craigavon Borough Council's environmental health department to investigate the outbreak.

Dr Neil Irvine, consultant in health protection at the agency, said: "The nursery remains closed and all appropriate infection control measures are being taken and the nursery is co-operating fully with the PHA."

Symptoms normally develop after ingesting contaminated foods or liquids or having been in contact with infected animals.