An Indonesian province hit by a haze outbreak has formed a team of more than 500 to hunt down people who started forest fires after the president demanded action, a report said Monday.

President Susilo Bambang Yudhoyono made the call during a weekend trip to Riau province on western Sumatra island, where authorities have declared a state of emergency after the fires -- many deliberately lit to clear land -- produced thick palls of smog.

The acrid smoke cloaked the province in recent weeks, disrupting flights, closing schools and prompting tens of thousands of people to seek treatment for respiratory illnesses.

It sparked fears of a repeat of a crisis last year when smog from Riau, where fires are set every year to clear land for palm oil plantations, cloaked neighbouring Singapore and Malaysia in thick haze.

Hundreds of personnel and aircraft have been deployed to combat the fires, although the emergency eased at the weekend when heavy rain swept over Sumatra and doused many of the blazes.

State news agency Antara reported Monday that a 558-strong team including police, military personnel and forest rangers had been formed to hunt down those responsible for starting the fires.

Slash and burn land clearance remains common on Sumatra even though it is illegal.

"The deployment of hundreds of personnel is mainly to strengthen legal enforcement," Riau police chief Condro Kirono was quoted as saying.

Police have so far named 65 people suspected of deliberately starting fires.

The crackdown came after Yudhoyono publicly criticised officials for their ineffective response and demanded more action on his trip to Riau.

The president, who has now returned to Jakarta, said Monday on Twitter that "the law must be firmly enforced, strongly and quickly" to prevent future haze outbreaks.

Sumatra, like Malaysia and Singapore, has suffered unusually dry weather in recent months which has prompted an early outbreak of forest fires.