Malaysia said today it would hold crisis talks with Indonesia over the choking haze caused by fires in Sumatra, which has reached hazardous levels and forced Kuala Lumpur's second airport to close.

In Port Klang, a major shipping centre just west of the capital Kuala Lumpur, the air pollution index shot up to 410. Several other parts of the country also recorded levels in excess of 300 which is considered officially "hazardous".

"If the API hits 500 we will declare it an emergency," Environment Minister Adenan Satem said. "The situation is not getting better, it is getting worse."

"The cabinet has also instructed me to go to Jakarta to meet our counterparts to identify long-term and short-term measures to fight the haze. We will try to go as soon as possible," he told a press conference.

Adenan showed satellite images of Indonesia's Riau and North Sumatra provinces on Sumatra island where hundreds of forest fires are raging, sending pollutants across the Malacca Strait and onto Malaysia's central west coast.

The minister also announced that the government had lifted an eight-year ban on releasing air pollution index (API) figures. The ban had been designed to protect tourism but has been sharply criticised here.

Health Minister Chua Soi Lek said the crisis was already having an impact on health, with clinics reporting a 150 percent increase in asthma attacks and higher rates of upper respiratory tract conditions and eye problems.

Subang airport closed

Kuala Lumpur's second airport at Subang was closed until further notice as visibility sank to less than 300 metres and contingency plans were made in case the country's main airport has to shut, Transport Minister Chan Kong Choy said.

So far, only one flight has been forced to divert from Kuala Lumpur International Airport but if the situation worsens traffic can be diverted to Langkawi, Penang and Johor Bahru, he told reporters.

In Kuala Lumpur office workers pressed handkerchiefs to their faces as they ventured outside. The tops of the Petronas Towers, once the world's tallest buildings, were almost invisible.

Under the air quality index, less than 50 is good, 51-100 is moderate, 101-200 is unhealthy, 200-300 is very unhealthy and more than 300 is hazardous.

In 1997 and 1998 choking haze caused mainly by Indonesian forest fires enveloped parts of Southeast Asia including Malaysia for months, causing an estimated 9.3 billion dollars in economic losses to the region.