The US government won't recommend closing schools with confirmed cases of A/H1N1 flu anymore, a senior official said on Tuesday.

Speaking at a news conference at the Atlanta-based Centers for Disease Control and Prevention (CDC), Health and Human Services Secretary Kathleen Sebelius said that since scientists now believe the A/H1N1 virus is no more dangerous than seasonal flu virus, schools should act accordingly.

Sick students need to be kept home for a week, "but schools should feel comfortable about opening," she said.

Schools that have been closed can reopen, Sebelius added.

Richard Besser, CDC's acting director, also explained that while in a pandemic, closing schools has a definite benefit, but closing during a general flu outbreak is not required.

He called the new school guidance as "a science-based decision that involves a lot of judgment."

The latest figure from the CDC said there are now 702 probable and 403 confirmed cases of the flu in 44 states.

The US Education Department said that more than 400 schools had closed as a result from the A/H1N1 flu, affecting about 245,000 children in 18 states.