JAKARTA (Reuters/AFP) - Indonesia is hoping for rain to help extinguish forest fires that have been smouldering for weeks, shrouding parts of South-east Asia in thick smog, a government official said on Thursday (Oct 1).

Indonesia has already spent millions and deployed thousands of firefighters and several water-bombing planes in its efforts to put out the fires, the official, Mr Willem Rampangilei, told reporters.

"The fires can only be put out by rain and water-bombing, so it needs time," said Mr Rampangilei, the head of Indonesia's national disaster management agency.

"We are hoping by the end of October or early November, the haze problem will be resolved."

The agency had previously hoped to put out the fires, which are often blamed on smallholders or plantation companies, by mid-October.

Mr Rampangilei also defended the country's efforts to fight the forest fires. "Are we able to manage the fires? The answer is clearly a yes... we are not overwhelmed, we can manage it and there is progress," he told reporters.

Singapore has offered to help in fighting the fires but Mr Rampangilei said it was not needed. "Indonesia welcomes the offer but at this moment, everything is under control," he said. "We can see some achievements, some progress that we have successfully extinguished a number of fires," he added.

More than 20,000 troops, police and other personnel have been sent to Sumatra and Kalimantan to fight the fires through waterbombing and chemically inducing rainfall. "Indonesia has tried all it could to douse the fires... and is still working very hard," he said.

For years, the region has suffered annual bouts of smog, caused by slash-and-burn farming in Indonesia's northern islands of Sumatra and Kalimantan, but governments' efforts to tackle the problem have failed.

A lengthy dry season in Indonesia this year has been worsened by the El Nino weather effect, making it harder to contain the fires in the absence of rains that usually arrive in November.

Growing pollution from the smog has disrupted flights and forced school closures in neighbouring Singapore and Malaysia, while thousands of people on the two Indonesian islands are reported to be battling respiratory diseases.

Indonesia has faced criticism from neighbours and green groups for not doing enough to prevent the fires, which cause millions of dollars worth of damage to health and the environment every year.

It has repeatedly turned down assistance from Singapore, which has offered water-bombing equipment and personnel to help put out the fires.

Indonesian officials, including Vice-President Jusuf Kalla, have repeatedly said they have enough resources to handle the crisis, with Mr Kalla adding that neighbouring countries should be grateful for clean air provided by Indonesia's rainforests outside the haze season.

Mr Rampangilei said Indonesia had the crisis under control. "We are very grateful but everything is under control and there is progress," he said, when asked why the government would not accept foreign assistance.

The Environment Ministry says it is taking legal action against four companies and is investigating about 200 more.

Singapore, where commuters have taken to wearing protective face masks, has urged Asia Pulp & Paper Co. to check if subsidiaries and suppliers have links to the forest fires.

The firm has said it will cooperate.