The World Health Organisation has warned that a pandemic outbreak is imminent
Northern Ireland is stepping up preparations for an outbreak of a swine flu pandemic.
Health Minister Michael McGimpsey said masks and protective clothing were being sent out to doctors' surgeries and all should be equipped by Friday.
The move follows the World Health Organisation's (WHO) decision to raise the current level of influenza pandemic alert from phase four to five.
"It is a strong signal that a pandemic is imminent," he said.
He said that the masks being sent to surgeries were equipped with respirators.
"The key advice is if you are feeling unwell don't go out of the house, stay at home, ring the GP and the GP will look after you," he said.
He added that the current medical advice was that the paper-type disposable masks featuring in coverage from the outbreak in Mexico would be of limited use in preventing infection.
"You would find a handkerchief just as useful," he said. "And it may give a false sense of security."
Acting Chief Medical Officer Dr Elizabeth Mitchell said a Northern Ireland swine flu helpline will open at midday to give advice. The free-phone number is 0800 0514 142.
"The key message to the public is not to be alarmed but to be prepared for a potential pandemic," she said.
"Evidence to date suggests that, other than in Mexico, the majority of cases have had a relatively mild flu-like illness which responds well to treatment with anti-virals.
"We have been planning for a situation like this for some years. In fact, the UK is recognised as among the best prepared for any potential pandemic.
"The preparations we have in place and are continuing to make, will help us respond well in the event of a pandemic.
"GPs across the country have been notified and made aware of the symptoms and what to do if they suspect a patient has pandemic flu. We have also purchased enough anti-virals to treat up to 50% of the population and are rapidly moving to buy enough to treat 75%."
The results of two tests for suspected swine flu in Northern Ireland will be known later on Thursday.
On Wednesday, 11 possible cases tested negative. Four people in the Irish Republic were also given the all-clear.
An emergency control centre has also been set up at Stormont to deal with any outbreak.