(Corrects headline and paragraph 1 to clarify that Sarawak has not declared an emergency and needs to request an official declaration)
KUALA LUMPUR, Sept 4 (Reuters) - Malaysia's Sarawak state has submitted a request to the federal government for the king to declare an emergency in the district of Serian on Friday, after thick haze caused by forest fires in neighbouring Indonesia pushed air pollution up to hazardous levels.
Sarawak, on Borneo, has been heavily affected by fires on the Indonesian side of the island, with haze forcing school closures in some parts of the state.
Malaysian authorities categorise Air Pollution Index (API) readings above 300 as hazardous, with a measurement of 500 serving as the threshold for declaring an emergency. The API measured 519 in Serian on Friday, government data showed.
(Reporting by Kuala Lumpur newsroom; Editing by David Stanway)
