Under the pollution emergency rules, Port Klang, Malaysia's biggest and busiest harbor, will be shut down. All educational institutions and government and private workplaces will also be closed, including factories, construction sites and quarries.

The haze has shrouded Kuala Lumpur and surrounding areas for more than a week in a pall of noxious fumes, smelling of ash and coal, in the country's worst environmental crisis since 1997.

The source of the haze is Indonesia's Sumatra Island, where farmers, plantation owners and miners have set hundreds of fires in the forests to clear land during dry weather. Winds blow most of the fumes across the narrow Strait of Malacca to Malaysia, although parts of Indonesia are also affected.

The fires are an annual occurrence, and Malaysian officials have expressed frustration over Indonesia's failure to tackle the problem. Indonesia's forestry minister, Malam Sambat Kaban, countered Thursday that 10 Malaysian firms clearing land in Indonesia had contributed to the fires.

The two countries did agree Thursday to use cloud seeding to try to induce rain over Sumatra to stop the burning of the forests.

Air Pollution Index Topped Emergency Level

The smoke has blown over the western coast of Malaysia, shrouding its biggest city, Kuala Lumpur, its capital, Putrajaya, the technology city Cyberjaya and the biggest port district, Port Klang.

"In my office, things look normal, but if I go down to the building's lobby area, I can smell smoke. Even in the basement car park I can smell smoke," said Liew Cow Yuan, a consultant with the DHL Express Global Data Center in Cyberjaya.

Prime Minister Abdullah Ahmad Badawi declared a state of emergency in Port Klang and in Kuala Selangor, a tourist area known for its fireflies, after the air pollution index topped 500 -- the emergency level.

The index measures harmful particles in the air, and Thursday was the first time the 500-level has been passed in Malaysia. A reading of above 300 is considered hazardous.

Under the emergency rules, Port Klang, the country's biggest and busiest harbor, will be shut down. All educational institutions and government and private workplaces will also be closed, including factories, construction sites and quarries.

However, supermarkets, shops selling food and drinks, pharmacies and essential services will remain open. Road work will be suspended and the use of personal cars and trucks will be discouraged.

Prime Minister Urges Prayers

Four other areas, including the financial capital Kuala Lumpur and Putrajaya, had air pollution levels above 300. Schools in and around Kuala Lumpur were closed Thursday and Friday.

But people went to work Thursday, many wearing surgical masks that offered little protection from the noxious air. Landmarks in Kuala Lumpur, such as the tops of the Petronas Twin Towers vanished in the haze. Acrid smoke seeped into office air-conditioning systems.

"The air is so bad that my eyes are stinging," said Gerard Miranda, a 31-year-old shopper. "I had breathing difficulties when I was outside this building, probably because I've a sinus problem that is being aggravated by the haze."

The prime minister urged people to seek divine help to overcome the crisis and called on mosques to hold special prayers for rain that would wash away the haze.

"This is my approach. When such things happen, we must also pray to God to seek help," Abdullah told reporters.

Malaysia rushed firefighters to Indonesia during a similar crisis in 1997-98, which caused large parts of Malaysia and Singapore to be enveloped in haze. Economic losses across the region then were estimated at $9.3 billion.

Travel agents said the haze would have minimal impact on tourism because key destinations such as Langkawi and Penang in northern Malaysia were not affected.

"So far we have not received any cancellations and it's peak tourist season right now," said Meloni Stevens, an agent dealing mostly with European tourists.

However, Malaysia's benchmark stock index slipped 0.4 percent Thursday amid worries that prolonged haze could undercut palm oil exports, tourism and other economic sectors.

The Meteorology Department said no respite was expected until October, when rains would help wash away the haze, a mixture of dust, ash, sulfur dioxide and carbon dioxide.