Twelve more people have fallen ill over the past 24 hours with stomach flu symptoms at Palmerston North Hospital.

An outbreak of norovirus has affected 62 staff and 36 patients at the hospital over the past fortnight.

Hospital spokeswoman Susan Moore says eight patients and four staff members are the latest to show symptoms of the virus. She says three wards at the hospital remain closed to new admissions and visitors are being asked to use the hand hygiene stations set up outside wards.