Indonesian President Susilo Bambang Yudhoyono has apologised to Singapore and Malaysia over fires that have cloaked the countries in thick haze, as thousands more emergency workers were deployed to tackle the blazes.
Southeast Asia's worst smog crisis for years pushed haze levels in Singapore to a record high last week, with residential buildings and skyscrapers shrouded and daily life for millions in the city state dramatically affected.
The smog has drifted north and is now badly affecting Malaysia, while in a badly-hit province on Indonesia's Sumatra island - where the fires are raging in peatland - hundreds gathered to pray for rain.
The crisis has triggered a war of words between Jakarta and its neighbours, with an Indonesian minister accusing Singapore of acting "like a child". However, Mr Yudhoyono sought to ease tensions by issuing a public apology late on Monday, AFP reports.
"As the president of Indonesia, I apologise for what has happened and ask for the understanding of the people of Malaysia and Singapore. We accept it is our responsibility to tackle the problem."
Singapore has repeatedly demanded that Indonesia step up action to tackle the fires, but Jakarta has hit back, saying palm oil companies from Singapore and Malaysia which run plantations on Sumatra also share the blame.
Smog from Sumatra is a recurring problem during the June-September dry season, when big companies and smallholders alike light fires to clear land, in a cheap but illegal method of clearing space for planting.
Southeast Asia suffered its worst smog outbreak in 1997-98 and was hit with a serious recurrence in 2006.
Indonesia's national disaster agency said on Tuesday more than 3000 emergency workers, including police and soldiers, would be sent over the next two days to Riau province, where the fires are centred.
There are already about 2300 personnel on the ground tackling the blazes and providing support to those affected, agency head Syamsul Ma'arif said. They are being supported by helicopters and planes dropping water and attempting to chemically induce rain through cloud-seeding.
However, agency official Agus Wibowo told AFP from Riau that airborne efforts to fight the blazes were proving ineffective, so the agency was shifting its focus to "sending more men to the affected areas to fight the blazes on land".
