Visitors to patients in wards at two hospitals in west Wales have been asked to stay away in a bid to contain an outbreak of a sickness bug.
Merlin ward at Carmarthen's Glangwili Hospital and Ward 7 at Withybush Hospital in Haverfordwest have been shut to visitors in a bid to prevent further infection.
The patients are said to have symptoms associated with gastroenteritis.
Gastroenteritis causes diarrhoea and vomiting and is easily spread.
Sharon Daniel, Assistant Director of Nursing (Infection Prevention & Control) at Hywel Dda University Health Board, said: "Illnesses such as diarrhoea and vomiting can pass from one person to another very easily and we have been informed that gastroenteritis is also circulating in the community.
"I would urge people who are feeling unwell or have been in contact with someone who has these symptoms not to visit patients in hospital at this time as viruses can be serious for sick and vulnerable patients."