By Jonathan Kent
BBC correspondent in Kuala Lumpur
Malaysia has announced that its first outbreak of bird flu is of a strain potentially deadly to humans.
Singapore has suspended Malaysian chicken imports
Agriculture Ministry Secretary General Abi Musa Asa'ari Mohamed Nor said tests showed the outbreak was caused by the H5N1 virus.
Meanwhile, the government is denying that it tried to cover up the outbreak after the national news agency ordered local media not to report the story.
The H5N1 strain has killed several people in East Asia this year.
It was announced on Wednesday that the H5 strain of the virus had been detected.
A day later the country's top agriculture official confirmed it was the N1 variant - the type which has been passed to humans.
However the opposition has accused the government of trying to cover up the outbreak.
Late on Wednesday the national news agency issued a note to editors saying the prime minister's office did not want it reported. Few papers carried the news.
However the government has since said it issued no such instruction.
Culling has already begun around the site of the outbreak at a village near the town of Kota Baru, close to the Thai border.
There is a strict 10km (6.25 mile) quarantine zone in force around the area.
Singapore has imposed a ban on the import of poultry, eggs and poultry products from Malaysia.
The four million inhabitants of the island state consume 120,000 Malaysian chickens, 20,000 ducks and 2m eggs every day.
The authorities in Singapore have warned there may be some shortages.