New York - New York City Mayor Michael Bloomberg said Monday that 28 cases of swine flu have been confirmed and another 17 cases were suspected in New York City, where more than 100 students at one school had become sick and were being tested. Bloomberg said at a news conference that it appeared the swine flu cases have been mild so far and precautions were needed to make sure that the health situation in New York is safe while authorities struggle to contain the flu.

All the flu cases are concentrated at a Queens high school, where local news reports said six of the original eight students who reported sick had travelled to Mexico for the spring break.

Bloomberg said the 45 total suspected and confirmed cases were from one single cluster of influenza. He said six students who reported sick at a daycare center tested negative.

"There is no other cluster of the flu in New York City," Bloomberg said. "In addition, nearly all the students confirmed with the swine flu at the Saint Francis school were improving. None of them as far as we know are getting worse."

He said City Hall had contacted all daycare centers in the city of 8 million people and found no case of swine flu, severe illness or possible cases of flu.

"This indicates that so far we have not seen a situation comparable to that of Mexico," Bloomberg said.

Bloomberg said that a great number of New Yorkers were requesting emergency treatment at hospitals, but their symptoms had nothing to do with the swine flu.

The mayor said the city has received offers, including masks, to help the population from contracting the illness. But he said New Yorkers need not wear masks for the time being because the illness appeared to be under control.

The US government has declared a national public health emergency after tests confirmed an initial 40 people in the United States, including the students at New York's Saint Francis school, have mild cases of the flu.

The Saint Francis high school in Fresh Meadows, Queens, where the eight students became sick, was closed Monday and Tuesday to allow cleaning crews to sanitize the school.

Local news reports said six of the eight ill students apparently contract the flu during spring break in Mexico. They said about 150 students at the same school reported flu-like symptoms and were submitted to tests, prompting talks of a mass school closings to thwart the flu's spread.(dpa)