A Belgian man is being treated in hospital with the symptoms of bird flu, according to the Belgian health minister.
The man is understood to have returned from China at the weekend, news agency Belga quoted the health minister as saying.
A Belgian health official emphasised it was a possible case of bird flu rather than a probable one.
Meanwhile, a nine-year-old girl has died of bird flu in China, state media said today. The girl, China's 10th known death from bird flu, died on Monday night in the eastern province of Zhejiang, the official Xinhua news agency said.
Her death comes days after the government confirmed that a 32-year-old man had died from the H5N1 virus in the southern province of Guangdong, near Hong Kong, triggering alarm there.
"The epidemic situation is very severe. Right now is spring, when there is a high chance of bird flu outbreaks due to the frequent movement of migratory birds. This epidemic has not been effectively controlled worldwide," China's deputy agriculture minister Yin Chengjie told reporters.
The virus has spread rapidly since the beginning of February, killing birds in more than 15 new countries as it moves deeper into Europe and Africa.
Albania became the latest European country to report a case of H5N1. The virus was detected in a chicken in the southern Sarande coastal region, close to the border with Greece.
Indian health officials said they had contained an outbreak in poultry, but the virus was still present in bird waste two weeks after the first cases were reported.
India has culled about 500,000 birds, destroyed 1.3 million eggs and launched a mass clean-up campaign in and around the western town of Navapur, where the country's first and only H5N1 cases in chickens were reported last month.
Sales of chicken in India have dived, prompting the government to launch an advertising drive to reassure consumers.
The WHO's Lee said Africa would get a "sizeable portion" of the $2 billion which rich nations have pledged to fight the disease. The H5N1 influenza virus was detected in domestic flocks in Egypt, Nigeria and Niger last month.
There are concerns that the continent, already saddled with HIV/AIDS and malaria, is ill-equipped to combat this new threat with meagre resources.