(AP) - Several hundred students have fallen ill at the New York school hit by a swine flu outbreak, city officials said Tuesday as the number of confirmed cases in the United States rose to 68, with at least seven people hospitalized.

A U.S. health official said deaths were likely.

"I fully expect we will see deaths from this infection," as swine flu cases are investigated, said Richard Besser, acting director of the federal Centers for Disease Control and Prevention.

New York has the largest number of swine flu cases, with a heavy concentration at a Catholic school in Queens where students recently went on a spring break trip to Mexico.

There were indications that the outbreak may have spread beyond the school, with two people having to be hospitalized and officials closing a school for autistic kids down the road. Those cases have not been confirmed.

"It is here and it is spreading," New York City Health Commissioner Thomas Frieden said. "We do not know whether it will continue to spread."

Mayor Michael Bloomberg said that 82 of 380 students at P.S. 177, a school for autistic children, have called in sick. A third school in Manhattan is being evaluated because students there are sick, Frieden said.

The CDC said the country has confirmed cases across six states, including New York, Ohio, Kansas, Texas, California and Indiana.

The increase is not surprising. For days, CDC officials have said they expected to see more confirmed cases - and more severe illnesses. Health officials across the country have stepped up efforts to look for cases, especially among people with flu-like illness who had traveled to Mexico.

CDC officials also had warned that updates in the number of confirmed cases would at time be disjointed, as different states announce new information before the CDC's national count is updated.

A handful of schools around the country have closed over swine flu fears and some people are wearing masks, but it's mostly business as usual in the U.S., even at border crossings intoMexico.