Five Malaysian navy sailors have been hospitalised for bird flu tests after possibly coming into contact with diseased birds while patrolling the disputed Spratly islands, officials said today.

The navy personnel had noticed that sparrows were dying in the area, the director of the Health Ministry's Disease Control Division, Ramlee Rahmat, told AFP .

"Five of them were admitted for observation at the Queen Elizabeth Hospital (in Sabah) after they developed a fever. We are taking precautionary measures as they were in contact with the birds," he said.

"We are not sure whether it is related to the dying birds and why the birds were dying, but we will investigate," he said.

The fear is that the birds had migrated from neighbouring countries hit by the bird flu virus, which the World Health Organisation fears could mutate into a highly contagious form that triggers a global human flu pandemic.

Tests out on Monday

Brunei, China, Malaysia, the Philippines, Taiwan and Vietnam claim sovereignty over all or part of the Spratly Islands, which straddle shipping lanes and fishing grounds in the South China Sea and are believed to contain vast oil and gas reserves.

Results of tests to determine whether the five sailors are suffering from bird flu are expected to be known Monday, Ramlee Rahmat said.

The deadly H5N1 strain of bird flu has killed 28 people in Vietnam and Thailand this year, and was detected just over a month ago in Malaysia's northeastern state of Kelantan.

The virus spread rapidly despite intense efforts by veterinary officials, prompting authorities to declare the entire state quarantined.