Malaysia is to send 1,200 firefighters to Indonesia to put out forest fires that have cast a blanket of smoke and mounting health fears across Southeast Asia.
Emergency alerts were stepped in both countries and Malaysia's Prime Minister Mahathir Mohamad urged the public to wear protective masks and appealed to them to share cars and use public transport to cut vehicle emissions.
In Indonesia, the haze again hampered efforts to fly supplies to six towns in the eastern province of Irian Jaya, where 251 people have died in a drought that caused an outbreak of cholera.
Malaysia will send 1,200 firefighters to the Indonesian island of Sumatra to battle blazes blamed for the smoke haze that has drifted over three countries. Around 200 fire engines have also been put on standby, Coordinating Minister for People's Welfare Azwar Anas said in Jakarta.
He added that Malaysia had offered to send air force medical and communication experts and help to start cloud seeding to produce rain to clear the smog.
In Kuala Lumpur, the index rose from 108 on Sunday to a ``very unhealthy'' 288 on Monday and hit 301 in the industrial area of Gombak, the department of environment said.
The pollution index in Sarawak on Borneo island surged to 649. Visibility in the state capital, Kuching, was cut to about 300 meters. Kuching airport was again closed barely 24 hours after it reopened on Sunday, leaving many passengers and tourists stranded. Other airports have also been closed.
Kuching is to be used as a base for a cloud seeding operation.
The Malaysian prime minister chaired a meeting which agreed all nurseries would close if the Air Pollution Index crosses the 300 hazardous level and all schools would close if the index breaches 400.
Mahathir has called in French and Japanese experts to help devise plans to clear the massive cloud of pollution.
``We realise this problem cannot be overcome easily but we are trying our best,'' Mahathir was reported saying by Bernama news agency.
An environment department expert said the haze was likely to remain until the monsoon season in October.
The Indonesian government has declared the fires in Sumatra island and in Kalimantan, the Indonesian part of Borneo, to be national disasters.
The Indonesian areas worst hit by the fires are Central Kalimantan and the Jambi province in central Sumatra, the welfare minister said in Jakarta. Other affected areas include West and East Kalimantan, Riau and South Sumatra.
Government and military personnel have been mobilized to fight the fires, Anas added.
A health ministry official has called on local officials in eight provinces in Kalimantan and Sumatra to consider closing schools, the Suara Pembaruan newspaper reported.
The Indonesian government warned 163 plantation firms last week that their licences would be revoked if they failed to stop their slash-and-burn land clearing in 15 days.
Indonesia is also facing its worst drought in half a century. The number of drought and cholera-related deaths in Irian Jaya has risen to 251 since mid-August as people in remote areas struggle to find clean water and food.
The smoke has stopped planes landing in the remote stricken districts.