The World Health Organization has lifted its travel warning for Hong Kong and China's Guangdong Province, indicating the spread of the disease SARS is under control in those areas. But officials say this does not mean the danger from SARS has passed.

Announcing the change, Dr. David Heymann, head of WHO's Division of Communicable Diseases, said Hong Kong and Guangdong have met the three criteria the organization had set.

Those three criteria involve the magnitude of the outbreak and the number of new cases occurring each day, the pattern of transmission within the area, and whether cases are being exported internationally.

"As of today, both Guangdong and Hong Kong have below 60 infectious cases of SARS and all are hospitalized," he announced. " In addition, in Hong Kong there have now been 20 days in which no cases have occurred in the community that were unexpected - in other words, all cases that are occurring are among contacts, known contacts, of previous SARS cases. And neither Guangdong nor Hong Kong has exported internationally cases of SARS within the past twenty days. So having fulfilled those criteria both Hong Kong and Guangdong province are removed from the list of travel recommendations today."

The World Health Organization's recommendation that travelers should postpone all but essential trips to Hong Kong and Guangdong was issued on April 2, in order to minimize the international spread of SARS.

And Dr. Heymann warned Friday that lifting the recommendation does not mean the SARS outbreak is over.

"This outbreak is not over in either Guangdong or Hong Kong and we will be constantly getting reports and validating those reports and it certainly is possible that a travel recommendation might have to be made again in the future," he explained. "This is being removed at present because of the information we have as of eight o'clock this morning Geneva time."

Dr. Heymann said screening should continue at airports. He says both places continue to have local transmission of the disease, and because of that they should continue to do screening of departing passengers, to ensure that infected or sick persons do not get onto international flights.

The WHO official also said it is extremely important that there should be a massive infusion of resources from the Chinese government and other sources to deal with SARS in parts of China where travel warnings are still in force. These include Beijing and five provinces.