Most regions of Sumatra are currently blanketed by smoke from land and forest fires and the pollution will potentially reach neighboring countries such as Malaysia and Singapore.

"From our data this morning, almost all of Sumatra is covered in smoke, with affected regions including South Sumatra, Jambi, West Sumatra, Riau, Medan and Aceh," said head of the Pekanbaru Meteorology, Climatology and Geophysics Agency (BMKG) Sugarin on Friday as quoted by Antara news agency.

Sugarin said that only a few areas were relatively free from air pollution, those including Lampung and parts of Bengkulu.

In Pekanbaru, for instance, the smoke was still thick on Friday afternoon and has reached a hazardous level of air pollution and caused visibility to drop to around 700 meters.

The smoke is said to be coming from land and forest fires in South Sumatra, Jambi and Riau, from which smoke is blown by the wind toward the north, increasing the possibility that it will reach neighboring countries.

According to data from NASA's Terra and Aqua satellites, there were up to 362 hot spots in Sumatra at 5 a.m. on Friday. Most of them were located in South Sumatra, where there were 173 hot spots, followed by Jambi with 148, Riau with 31, and Bangka Belitung with 8. (kes)