The warning came after some high school students were seen out shopping and visiting other schools despite being told to stay home and avoid public contact because of possible exposure to severe acute respiratory syndrome.

In a bid to emphasize the need to observe quarantine rules, Ontario Health Minister Tony Clement said he would chain people to their beds if all else fails.

"The minister does not think we have to get to that point," said spokesman Paul Cantin. "But people need to understand the context of it. I don't think anyone is seriously talking about using a chain to a bed, but there is a power to detain people as a last resort."

Those breaking the rules risk being hit with fines of C$5,000 ($3,650) a day or court-ordered isolation.

More than 5,000 people in Toronto and its suburbs have been ordered into precautionary quarantines as the area wrestles with the SARS outbreak, which has killed 31 people.

The Toronto area lists 52 probable cases of the deadly illness, with 17 patients critically ill and another 174 being monitored for infection.

On Monday, authorities were investigating another five deaths that may be linked to SARS.

Health authorities in York Region north of Toronto, where 1,500 high school students were sent into in quarantine, say they were informed that 10 to 20 of the students had been seen in the community. But when they called to check, the students were at home so no legal action has been taken.

Patrick Casey, a spokesman with the health department in York, said the students ordered into quarantine are "asymptomatic, which is a good thing; however, they do have the possibility of being exposed to SARS and the risk is we could see it spread by people violating their quarantine."

The students' quarantine ends on June 2.

QUARANTINE RULES

SARS quarantine rules require wearing a surgical mask when you are in the same room as another family member, sleeping in separate rooms if possible, not sharing any personal items such as towels and utensils, and bathing rather than showering as water droplets can spread the virus. Isolation lasts 10 days.

"People are obviously inconvenienced," said Dr. Jim Young, Ontario's commissioner of public safety. "But they have to do it."

For those who do not comply with voluntary isolation, a health officer can issue a "Section 22" order to keep them in quarantine, and fine them C$5,000 a day if convicted.

For those who defy the order, health officials can get a court order for hospital isolation under police guard.

Toronto health authorities have issued five Section 22 orders during the outbreak of SARS, which emerged about 10 days ago. They had issued 19 during the previous outbreak in March and April. No new Section 22 orders have been issued in York, where the previous outbreak saw 14 issued.

"If those who are minors who should be in quarantine, and they think they might be able to step around this, the joke is on them because their parents could be the one subject to the C$5,000 fine, " said John Letherby, a spokesman for Ontario's health ministry.

($1=$1.37 Canadian)