HONG KONG (AP) -- Death tolls from SARS in China and Hong Kong surged above 100 each on Wednesday as the World Health Organization said it was investigating theories that the disease may have been spread by sewage leaks, personal contact or even cockroaches and rats.

Schools in Beijing were ordered to close, affecting 1.7 million students, as the Chinese capital sought to stem the disease's spread, and thousands of nervous people in white gauze masks gathered in train stations to get out of town.

"We're really afraid to ride this train to go home," said one girl from the eastern city of Hangzhou, who would give only her surname, Shi. "We just don't know how dangerous this SARS is."

In Taiwan, staff at a Taipei hospital were tested and quarantined after at least seven workers developed symptoms following their possible infection by a patient. Nine new SARS cases in Taiwan raised its total to 37.

Severe acute respiratory syndrome has sickened more than 4,000 people worldwide and killed at least 251. On Wednesday, China announced nine new fatalities -- seven of them in Beijing - raising the mainland's SARS death toll to 106. Hong Kong's toll rose to 105 with six new deaths.

One of the Hong Kong deaths was a 34-year-old woman who gave birth to a child by Caesarean section while suffering from SARS. Three babies have been born this way and two of the mothers have subsequently died. The infants remain hospitalized, although they have tested negative for SARS.

Travel and tourism in the region have been devastated, particularly in Hong Kong.

WHO imposed a travel warning against the former British colony after a disturbingly virulent outbreak in an apartment complex, the Amoy Gardens. More than 300 residents were infected and 14 have died.

A Hong Kong government report last week said sewage leaks, personal contact and other factors, including rats and roaches that picked up the SARS virus on their bodies, may have caused the spread.

Not fully convinced, WHO plans to conduct its own investigation.

WHO wants a "complete and satisfactory understanding" of what happened at Amoy Gardens, as well as evidence a repeat is unlikely, before the travel advisory is lifted, spokesman Peter Cordingley said from the agency's regional office in Manila.

The Geneva-based WHO also needs to see Hong Kong's daily new infection numbers coming down, Cordingley said.

Hong Kong Health Secretary Dr. Yeoh Eng-kiong defended the Amoy Gardens report as "quite comprehensive" and said the WHO officials were coming at Hong Kong's request.

Hong Kong government officials say numbers of new cases are already dropping steadily, though the daily tally remains in the double digits.

Hoping to ease the economic strain from SARS, Hong Kong will refund taxes, temporarily lower some charges and guarantee bank loans as part of an 11.8 billion Hong Kong dollar (US$1.5 billion) package announced Wednesday by Chief Executive Tung Chee-hwa.

The school closure in Beijing begins Thursday, the city's education commission said. Hong Kong closed its schools for about three weeks as a precaution against SARS, but most secondary students went back to class on Tuesday. Younger students are expected to return soon.

In the western Indian town of Pune, medical staff who feared they would catch SARS forced three patients with the disease to move to a government hospital Wednesday, then closed their private medical center and quarantined themselves inside.

The transferred patients included a bride who was allowed to go ahead with her wedding even though she and her mother had symptoms of SARS. Wedding guests were quarantined to see if they get sick.

"There was panic among hospital staff because they handled these patients before they were declared SARS-infected," said Baburao Gaikwad, Pune's deputy director of health services.

In Japan, where no SARS cases have been confirmed, officials said a thermal imaging camera will be installed at Tokyo's Narita international airport to identify arriving passengers who have high fevers - a prime SARS symptom, along with breathing difficulties and coughing.

In Singapore, where thermal imaging scanners were placed at Changi Airport last week, authorities said they would also place units at the city-state's border with Malaysia.

Those who show up on the camera screen as "hot bodies," or with a temperature greater than 37.5 degrees Celsius (99.5 degrees Fahrenheit), will be pulled aside.

Other measures are in place in airports around the Asian region because of fears that SARS has been spread around the world by air travelers. Hong Kong said it would begin screening people crossing by land from mainland China.

In the Philippines, an X-ray technician at a Manila hospital is suspected of contracting the virus.

The Philippines has no confirmed SARS cases, but authorities fear a Filipino nurse may have spread it when she returned from Canada earlier this month and died of pneumonia.

Copyright 2003 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.