"We don't have this infection. We are focusing to prevent the disease from entering the country," Vineet Chawdhry, joint secretary in the Ministry of Health, told reporters.

"We don't need to panic. We need to be concerned and take some precautionary measures. The government is monitoring the situation and will handle it," he added.

J.P. Narain, director communicable disease in the WHO regional office for Southeast Asia, said : "There has been no suspected case in India."

Chawdhry said the Indian government has increased the stockpiling of Tamiflu - a globally recognised medicine to combat avian flue - to 10 million and it will be made available within seven days.

"The government is talking to four pharmaceutical companies and medicines will be acquired on the basis of rate query," he said, adding that the health ministry is talking to Ranbaxy, Cipla, Hetro Drugs Roche India.

Chawdhry said health authorities had identified 50,000 tourists who have entered India from flu-affected countries like New Zealand, Mexico, the US, Canada, Spain, France and Britain and they would be screened. India has also included in its list citizens coming from Austria and Israel.

He said travelers especially coming from Mexico would be traced.

"Our surveillance is in place and we have started screening passengers at the international airports," he added.

Passengers will be screened for visible signs of flu like cold, fever and upper respiratory infection. If anybody is found with the symptoms, they would be isolated and put on Tamiflu.

The WHO in Geneva Wednesday night raised the pandemic alert for swine flu by one level to Phase 5 - second-highest phase. The declaration of Phase 5 by WHO Director General Margaret Chan is a strong signal that a pandemic is imminent, but not inevitable. The second-highest phase is characterised by human-to-human spread of the virus in at least two countries in one WHO region.

The WHO official said there is a "strong signal that a pandemic is imminent".

"India is quite prepared and has the capacity to deal with any outbreak. We have the surveillance in place," Narain said.

In Mexico, the epicentre of the outbreak, there have been close to 160 deaths and nearly 2,500 infections due to the disease.

Of the infected cases, more than 1,300 are in hospital, but most have not yet been identified as swine flu cases. Apart from Mexico, WHO reported confirmed swine flu cases in Canada, the US, Israel, Spain, Britain and New Zealand. Costa Rica also reported two confirmed cases.