China said it may execute SARS patients who violate quarantine in the most radical step so far to contain the epidemic, as Taiwan struggled to prevent new outbreaks among health workers. A case of the respiratory disease SARS has been confirmed in Britain for the first time, British health officials said. Severe Acute Respiratory Syndrome (SARS) claimed four more lives in China, seven in Hong Kong and five in Taiwan Thursday, health officials said. Chinese Premier Wen Jiabao backed legislation allowing for the execution or life imprisonment of anyone who violates quarantine and spreads the disease. "We must heavily stress the importance of using legal methods ... and fully bring into the play legal weapons to win the war in preventing SARS," Wen was quoted by state television as saying. His comments came after the Supreme People's Court and the Supreme People's Procuratorate issued an interpretation on the infectious diseases law that took effect Thursday. "Intentionally spreading sudden contagious disease pathogens that endangers public security or leads to serious personal injury, death or heavy loss of public or private property will be punishable by 10 years to life imprisonment or the death penalty," Xinhua news agency said of the ruling. The World Health Organization immediately expressed concern that the draconian law could deter possible SARS patients from going to hospital. "There is a fine balance with this kind of disease where you need to isolate and quarantine patients, but if you are too heavy handed it may end up only stigmatizing people," WHO spokeswoman Mangai Balasegaram said. China, the epicentre of the outbreak with 5,163 cases and 271 deaths, reported 52 new infections -- its lowest number since the government admitted covering up the epidemic on April 20. But China insisted that the situation was improving and there was little sign of widespread infections in its heavily-populated and poorly-equipped countryside. The numbers of new infections in China has been steadily falling, although some experts have raised doubts about its reporting methods. Officials in Taiwan were under pressure to contain the spread of the virus among health workers as another hospital shut its emergency and outpatient services. Officials at the private Chang Gung Memorial Hospital in Kaohsiung quarantined 600 in-patients after 15 staff became infected. The private Mackay Memorial Hospital reported seven SARS cases involving medical workers who had treated a noodle stand proprietor who was later confirmed to have died of SARS. Three other hospitals have closed or quarantined patients and staff because of SARS. Taiwan Thursday reported 26 more infections and five deaths, including that of a doctor, taking the death toll on the island to 34 from 264 cases. "Infections at hospitals in the past two days are getting serious ... more than what we had expected," said Li Ming-liang, commander of the national anti-SARS task force. In Britain, the Health Protection Agency said a SARS patient, whose identity and location was not revealed, was no longer considered in danger, and there was no risk that the patient had passed the disease to anyone else. The patient was one of eight people so far classified as probable SARS cases in Britain. In Singapore, more patients and staff from the Institute of Mental Health have been quarantined because of SARS fears, the health ministry said. And in the Philippines two new SARS cases were reported, taking the country's total caseload to 12. However, both patients have recovered. The Philippines has reported two deaths from the virus. Five new cases emerged Thursday in Hong Kong and seven deaths were reported. The territory's death toll stands at 234 from 1,703 infections. Other deaths have occurred in Vietnam (5), Malaysia (2), Singapore (28) and Thailand (2). More than 600 people have succumbed to the disease worldwide. Canada, the only country outside of Asia to record SARS deaths, was celebrating Thursday after the WHO declared the virus was no longer spreading in the country and lifted the last remaining travel advisories. The WHO said it considered the chain of transmission was broken in Toronto, Canada's worst affected area, as no new locally-contracted case had been diagnosed there for more than 20 days. Canada recorded 24 deaths after a 78-year-old elderly woman first brought the virus to Toronto in March from Hong Kong. Russia would close down 31 out of 52 border crossings with neighbouring China and Mongolia in an effort to ward off the virus, the country's chief medical officer said Thursday. Gennady Onishchenko said the main entry points would "continue working" but smaller frontier posts and those offering simplified border checks would be temporarily shut. **PHOTO CAPTION*** A discarded surgical mask lies on the sidewalk outside SARS clinic setup of Sunnybrook & Women's hospital in Toronto. The number of active probable cases of SARS in Canada fell four to 12.(AFP/File/J.P. Moczulski)