Popular Thai holiday islands are being blanketed by haze from Indonesian forest fires, forcing several planes packed with tourists to turn back due to poor visibility.
The travel disruptions came as Indonesia finally agreed to accept international help to fight fires that have been started deliberately to clear agricultural land.
Five flights bound for the resort islands of Phuket and Samui turned back to Bangkok on Thursday, according to the Aeronautical Radio of Thailand, which controls air traffic across the country.
A further two airlines flying to Phuket from Singapore were forced to circle the airport for up to an hour before landing, it said.
"It is the worst haze [on the island] in many years," said Trakul Thotham, director of the department of disaster prevention and mitigation on Phuket.
However, he said the smog was "getting better" on Thursday.
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Of the seven affected southern Thai provinces, Phuket has been worst-hit with unhealthy levels of particulates in the air, according to the department.
Wipa Emem, a reservation clerk at the Holiday Inn Resort on the island, said some Thais wore protective masks to combat the pollution, but tourists were mostly "still on the beach".
Fires illegally started to clear land for plantations on Sumatra and the Indonesian part of Borneo have shrouded Singapore and Malaysia in acrid smog, worsening air quality, closing schools and forcing the cancellation of outdoor events
After weeks of insisting it could tackle the crisis alone, Indonesia said it was in talks with countries about assistance including Australia, Singapore, Russia, Malaysia and China.
"Hopefully, we can speed up our efforts," president Joko Widodo told reporters before flying to Jambi, one of the worst-affected provinces on western Sumatra island.
But his jet was unable to land at the local airport due to the haze and forced to divert to another airport on Sumatra, presidential spokesman Ari Dwipayana said.
The blazes are an annual occurrence during the dry season, but scientists have warned this year's are on track to be the worst ever due to an El Nino weather system that has created tinder-dry conditions in Indonesia.
Jakarta has deployed about 25,000 personnel and aircraft, but the fire-fighters have seemed overwhelmed by the extent of the blazes.
On Thursday there was some respite from the haze for Singaporeans and Malaysians with air quality recording moderate levels.