BEIJING (AP) - China shut down a major hospital in Beijing and put more than 2,000 employees under observation for severe acute respiratory syndrome today, as Hong Kong health experts said the disease may be even deadlier than originally thought.

Canadian officials, meanwhile, reacted with anger after the World Health Organization warned travelers against going to Toronto, the worst-infected area outside Asia.

As efforts to contain the virus intensified, Singapore was refurbishing a drug rehabilitation camp to hold anyone who violates an order to stay under home quarantine.

Worldwide, the death toll has passed 260, with more than 4,300 cases of infection reported.

The People's Hospital of Peking University was being disinfected and its patients and more than 2,000 employees moved to one of six hospitals in Beijing designated to handle severe acute respiratory syndrome, the university said.

It did not say how many patients were involved, but the Web site for People's Hospital says it has 1,020 beds.

The hospital's front gate was closed and a sign said patients, employees and all items used in the building were barred from leaving.

Visitors left bags of food and clothes, which the guard handed through the gate to masked hospital employees.

Nationwide, China has reported 110 deaths and more than 2,400 people sickened from SARS. Anxious Beijing residents cleared supermarket shelves of food today amid unease about possible shortages.

''You should have seen it. Lines at the cash registers stretched all the way to the store's back wall,'' said a clerk at a Jingkelong Supermarket who identified herself only as Li.

In Hong Kong, health officials revised the territory's SARS death rate to 7.2 percent of all reported cases, from about 5 percent earlier. Officials fear it may rise further.