Indonesia has put warships on standby to evacuate people affected by acrid haze from forest fires which has killed at least 10 and caused respiratory illnesses in half a million, officials said Saturday.

For nearly two months, thousands of fires caused by slash-and-burn farming in Indonesia have choked vast expanses of Southeast Asia, forcing schools to close and scores of flights and some international events to be cancelled.

The government has decided to send ships to haze-affected provinces to evacuate victims, especially children and women, if necessary, with two warships deployed to Kalimantan on Friday and another carrying medical workers and health equipment expected Saturday.

Military spokesman Tatang Sulaiman said the warships, which will be standing by in Banjarmasin, the capital of south Kalimantan, could serve as evacuation centers and hospitals for those affected by the haze.

Tatang said there was no immediate plan to bring people onboard but that could change if hospitals on land reach capacity or become overwhelmed.

"The ships are sent just in case children or pregnant women must be relocated from the local health facilities, it does not mean everyone would be put into the ships," Tatang said.

"So far health facilities on the ground in Kalimantan are still trying their best, we are just getting ready by deploying warships," Tatang said.

Each warship can carry up to 2000 people and has 344 beds onboard.

"For now the ships will be standing by. We will begin evacuation when there is an instruction from the government," navy spokesman Muhammad Zainuddin told AFP.

- 'Extraordinary crime' -

The government has deployed around 30 aircraft to fight the fires and for cloud seeding with 22,000 troops on the ground to combat the blazes.

Indonesian disaster mitigation agency spokesman Sutopo Purwo Nugroho said the fires had killed 10 people so far, some fighting the blazes while others died of respiratory illnesses or medical conditions exacerbated by the pollution.

"The impact of the forest fires has caused 10 people in Sumatra and Kalimantan to die, directly and indirectly," Nugroho said.

The figure did not include seven hikers killed in a wildfire on Java last week.

The agency estimated at least half a million people have suffered from respiratory illness since the fires started in July and 43 million people have been affected in the islands of Sumatra and Kalimantan.

Nugroho said the figure was likely just the tip of the iceberg because many people did not go to health facilities for treatment.

More than 1.7 million hectares (4.2 million acres) of land has been burned and six provinces severely affected by the haze, according to Indonesia's forestry ministry.

"This is due to human acts because 99 percent of forest fires were started deliberately. This is an extraordinary crime against humanity," Nugroho said.

Other countries such as Malaysia, Singapore, Australia and Japan have sent assistance to help Indonesia fighting the forest fires.

With Malaysia, Singapore and parts of Thailand already affected, the Philippines Friday said the haze had now spread there, disrupting air traffic and prompting warnings for residents to wear face masks.