While the 35-year-old London-based NRI was brought to hospital directly from the Indira Gandhi International Airport this morning, the 25-year-old who came from Texas got himself admitted to the RML last evening.

"Both of them are under observation in isolation ward. We have done all tests and samples have been sent to National Institute of Communicable Diseases (NICD)," N K Chaturvedi, Medical Superintendent of RML, told reporters.

The London-based NRI, who hails from Delhi, developed flu symptoms during his flight to the national capital from London and was referred to the hospital after a screening at the airport, he said.

"He has a running nose, soar throat and cold but has no fever. He will be kept under observation for the next three days," Chaturvedi said.

The Texas-based youth, who landed in Delhi on April 19 and had fever for two days on April 24, turned up at the hospital last evening, Chaturvedi said adding the man, who hails from adjoining Ghaziabad, later became asymptomatic.

"However, due to media coverage, he himself turned up at the hospital. We have kept him under observation in the isolation ward. As of now there are no symptoms," he said.

A senior Health Ministry official said four to five persons were brought to RML in the past 24 hours but they were discharged as they did not show any symptoms of the H1NI flu.

Chaturvedi said two others were brought to the hospital suspecting that they could be carriers of flu but it later turned out that they have liver problems. He said RML is fully equipped to handle cases of H1N1 flu.

"We have a full-fledged isolation ward which has 30 beds. There are 20 doctors and 12 nurses on duty. We also have 1,000 Tamiflu tablets. If there is a shortage of Tamiflu tablets then the NICD will provide it," he said.

The team of doctors comprises general physicians, ENT specialists, paediatricians and micro-biologists, he said.

The RML also has 100 medical kits which consists of protective gowns, gloves, eye-gears, syringes and scissors.

With the H1N1 flu spreading to more countries across the globe, the Government has said a total of 2,000 passengers, who have come in from the affected countries, have already been tracked and are being kept under watch.