Large parts of Sumatra and Kalimantan were choking in a thick haze yesterday, but Environment and Forestry Minister Siti Nurbaya Bakar was reported to have said that Indonesia has no need for Singapore's offer of aircraft to fight the growing outbreaks of fires.

In Malaysia, 18 areas recorded unhealthy pollution levels yesterday morning, including Kuala Lumpur, its neighbouring states and Sarawak on Borneo island.

The number of fires in Indonesia has soared in recent weeks and Singapore has offered help to combat them. The assistance package offered to Indonesia included a C-130 military transport plane for cloud seeding, up to two C-130s to ferry a firefighting assistance team from Singapore to Indonesia and a Chinook helicopter with a water bucket for aerial firefighting.

Ms Siti said that Indonesia had enough planes and equipment to deal with the crisis.

Her comments were confirmed by the ministry's chief spokesman, Mr Eka Soegiri, when The Sunday Times contacted him yesterday.

In a statement last night, the Ministry of Defence (Mindef) confirmed that, for now, the Singapore Armed Forces (SAF) would not be deployed to Sumatra.

"While the Indonesian authorities accepted our offer of assistance initially, they have since expressed appreciation for the offer and said they have sufficient resources of their own for now.

"Mindef/SAF remains in close contact with the Indonesia authorities and stands ready to help if required," the statement said.

The number of hot spots in Indonesia has surpassed the number recorded in mid-2013, when uncontrolled fires in Sumatra triggered record levels of haze in Malaysia and Singapore.

The Pollutant Standards Index hit 401 in June that year.

This time round, there were more fires in Kalimantan than in Sumatra, said Mr Andika Putraditama, a Jakarta-based research analyst at the Washington-based World Resources Institute (WRI), a global research organisation that provides data analysis on the fires.

Current wind patterns mean the haze above Kalimantan will affect Sarawak, but not Singapore.

The crisis, though, is no less severe in Sumatra, with hundreds of fires reported within plantation concessions and nearly half the fires affecting peat lands.

Jambi and South Sumatra provinces have recorded the most fires in the past week.

An analysis by WRI between Sept 5 and yesterday showed more than 400 fire alerts in pulpwood concessions in Sumatra. WRI named nine companies, including one firm with 219 fire alerts. The majority of the companies are listed as suppliers to Singapore-based Asia Pulp & Paper. The analysis lists 44 fire alerts for palm oil concessions in Sumatra.

In Pekanbaru, the capital of Riau province, thick haze paralysed Sultan Syarif Kasim II Airport yesterday, reducing visibility to only 100m, Jakarta Post reported. "No planes could fly," said airport duty manager Hasnan.

In Palembang, South Sumatra, the worst-affected province on the island, hundreds of residents held a mass prayer yesterday.

"We ask God to promptly give us rain. What we do here should complement the firefighters' efforts in the field," Mr Fajar Sani Nasution, a Palembang resident, told reporters.