Canada's largest city avoided a new World Health Organization (searchtravel advisory over SARS, and health officials said Tuesday the latest outbreak of the pneumonia-like virus appeared to be tailing off.

The U.N. health agency discussed the possibility of warning against travel to Toronto (search) but decided the new cases appeared under control with no spread in the general population, a spokeswoman in Geneva said.

In Toronto, health officials raised the number of probable SARS (search) cases by two to a total 64. More than 200 people with possible symptoms of severe acute respiratory syndrome were being monitored, and some of them were likely to be added to the probable cases list, officials said.

"It looks like the beginning of the tail-off, but I want to stress, we're not yet out of the woods," said Dr. Colin D'Cunha, the Ontario commissioner of public health.

More than 5,000 people remained in home quarantine because of possible SARS exposure, but 1,700 students returned to their suburban high school for the first time in a week after their 10-day isolation ended. None got sick after one student attended classes May 21-23 while having SARS-like symptoms.

The biggest outbreak of SARS outside of Asia has killed 32 people in the Toronto area, and the growing number of cases in a new cluster first announced May 22 attracted special attention from the WHO.

Health officials thought they had the illness under control after the initial cluster appeared in March and April, but an undiagnosed case at North York General Hospital led to a further spread among other patients, family members and health care workers.

Complaints by nurses that their warnings in mid-May of a new cluster went unheeded caused Ontario officials to announce a review of the situation Monday.

A new WHO travel advisory would devastate the city already reeling from the SARS outbreak, which has overwhelmed the health care system and hurt the vital convention and tourism industry.

But while the WHO was concerned about the increasing number of cases in Toronto, it decided not to impose a new advisory Tuesday because the new cluster appeared limited to hospitals, said Maria Cheng, a spokesperson for the WHO communicable diseases division.

"We are optimistic that Toronto is able to contain this outbreak," she said. "To us, it still looks very much like the transmission of SARS is confined to the hospital setting and there is no general public transmission of SARS."

The U.N. agency issued a travel advisory for Toronto after the first cluster appeared, but rescinded it a week later after Canadian officials complained it was unwarranted and promised better screening of international travelers for SARS.

The second cluster of SARS cases has landed Toronto back on a WHO list of SARS-affected cities or regions. The U.S. Centers for Disease Control and Prevention has reinstated a travel alert for Toronto, informing travelers of a health concern there.

WHO officials said they were checking out rumors of possible cases spread elsewhere from Canada, but Dr. James Young, the Ontario commissioner of public safety, said Tuesday he was unaware of them.

"We're not seeing surprises at this point in time, and that's positive," Young said. Still, hospital workers delivering patient care will continue to wear protective gloves, masks and gowns for now, he said.

"We want to see we have control of the situation before we relax the rules," Young said.

Three deaths being checked for possible SARS have been removed from suspicion, Young said, while two more remain under investigation.