A hospital ward has been closed to new patients after an outbreak of sickness bug norovirus.
The discovery at Wrexham Maelor Hospital comes days after two wards were closed at Colwyn Bay Community Hospital for the same reason.
Betsi Cadwaladr University Health Board said the Colwyn Bay outbreak had now been dealt with and the wards reopened.
The new incidence of the sickness and diarrhoea virus is an isolated one it said, with no other wards at Wrexham Maelor or other sites affected.
The board said healthy people can get the virus with a few days of being exposed to it and will generally recover within a few days.

However it can be much mores serious for those who are ill, the young and the elderly.
A spokeswoman for Betsi Cadwaladr said: "If you experience sudden diarrhoea and vomiting, our advice is to stay at home until you're feeling better.
"Try to avoid coming to hospital, as norovirus can spread to others very easily. Call your GP or NHS Direct on 0845 46 47 if you are concerned or need any advice.
"We want members of the public to help us prevent the risk of infection.
"If you have recently felt unwell with symptoms of norovirus or flu, please don’t come in to hospital to visit friends or family, or for an appointment.
"It is vital that that everyone follows the key rules to protect themselves, their families and, especially, our patients."

The airborne virus can be transferred from surface to surface so it is vital people wash their hands with soap and water. Alcohol hand gel is not always effective against the virus.
The health board has issued rules for the containment of the virus:
- Visitors must not come into any of our hospitals if they have suffered from diarrhoea and/or vomiting in the previous 48 hours.
- Patients who are due to come in but have had either diarrhoea or vomiting in the previous 48 hours are asked to contact us first for advice, and so we can make appropriate arrangements.
- All visitors to our hospitals should follow the advice on the signs and notices at ward entrances and any guidance from nursing or other staff.
- Please only visit affected wards if you really need to. Children should not visit affected wards.
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Everyone entering and leaving a ward must use the hand rub or wash their hands.
Norovirus advice
Although norovirus is unpleasant, for most people who are generally healthy it is a short lived illness of two or three days and does not require specialist treatment or a hospital admission.
People with symptoms of diarrhoea and vomiting should drink plenty of fluids to ensure that they do not become dehydrated
Virus particles land in the room where they have had diarrhoea or vomited. These virus particles cannot be seen, but will settle on surfaces in the room. If a person then touches those surfaces, and does not wash their hands immediately afterwards, they can also become infected with norovirus
The spokeswoman added: "The best way for members of the public to protect themselves is to ensure they wash their hands after visiting the toilet, and before eating, and avoid contact with people suffering from diarrhoea and/or vomiting."