Asserting that the high-risk period for avian flu has passed, a Hong Kong trade official Monday sought to alleviate Japanese tourists' concerns about the disease that has killed six people so far in the former British colony."Hong Kong is a very safe place to visit. There is no need for restrictions on visitors or quarantine," said Paul S.W. Leung, principal representative in Tokyo of the Hong Kong Economic and Trade Office.The disease, known as the "bird flu," is a new strain of influenza that reportedly originated with poultry imported from mainland China to Hong Kong. It is believed to be transmitted to humans via chickens carrying a virus. So far, the disease has been blamed for the deaths of six people in Hong Kong, and 18 other cases of infection have been confirmed."We will resume importing chickens from mainland China after safety is confirmed, but we don't know when it will be," Leung said. Since the outbreak began last August, the Hong Kong government has conducted thorough cleansing of poultry farms and stopped importing chickens from mainland China, Leung said.Hong Kong has also slaughtered some 1.3 million of the fowl in an attempt to eradicate the deadly disease's suspected source. Major hotels in the former colony have stopped serving dishes that use chicken, and only frozen chicken imported from countries that include the United States and Brazil is available for consumption.Asked whether fear of offending China may be hampering thorough research into the disease, Leung said the Hong Kong and Chinese governments have been duly cooperating. He also said the Chinese government spontaneously suspended poultry exports to Hong Kong late last year."There has been no new cases of the avian flu confirmed since Dec. 29," Leung stressed. "The period of high risk has passed. But we continue monitoring and cleansing to make sure there is no virus anymore."Meanwhile, one province in China has banned chicken imports from a neighboring province suspected to be the origin of the virus, and poultry sales in Beijing have fallen off drastically.