More than 300 guests reported suffering symptoms

More than 100 holidaymakers at the Butlin's Holiday Centre in Minehead remain ill with what is thought to be the Norwalk virus.

A total of 26 new cases were reported on Thursday, compared with 34 on Wednesday, and specialist cleaning measures have been carried out throughout the resort.

Altogether, more than 300 people have reported suffering symptoms since the outbreak began on Monday.

I think illnesses like this are getting increasingly common up and down the country Darren Hollis Centre Director Butlin

A spokesman for Somerset Health Authority, which has not closed the centre, said it was monitoring the situation daily.

Tests are still under way to determine if the virus is the Norwalk bug, which is highly contagious and causes vomiting and stomach upsets, but is not life-threatening.

There are around 8,000 guests at an Easter Christian festival at the holiday centre, and Butlin's have said the Spring Harvest event there is still going ahead.

The BBC's Songs of Praise is due to film at the Festival on Saturday, and says this will also still take place.

Centre Director Darren Hollis said: "We have advised all the guests on site of the situation and have written to all guests who are arriving within the next week.

"We have also issued advice on prevention, such as washing hands before meals and after using the toilet.

'Winter vomiting'

"I feel sorry for customers who have been here and been struck down by the illness, but I think illnesses like this are getting increasingly common up and down the country."

One guest said: "It's unfortunate for a lot of people that have paid a lot of money to come here."

Karen Anderson of the Health Protection Unit said: "We are aware that the illness is very predominant at the moment.

"It was associated with winter vomiting - that's what it was known as - but it appears to be spreading to throughout the whole year now."

Somerset Health Protection Unit and West Somerset District Council's Environmental Health Department were first notified of the outbreak on Monday.

A spokesman for Somerset Health Protection Unit said the infection was not thought to be connected with food consumption.

Testing

He said: "Gastric illness of this type commonly occurs within the community and often affects hospitals, schools and nurseries.

"The symptoms usually last for 24 to 48 hours. Whilst unpleasant, the illness is not normally life threatening.

"People affected usually recover after a few days rest, during which time they should drink plenty of water."

Health officials expect to identify the cause of the illness in a few days after testing has been completed.