JAKARTA, Indonesia — The authorities shut most schools in parts of Indonesia’s Sumatra island to protect children from a thick, noxious haze as deliberately set fires burned through peatland forests, they said Wednesday.
The Disaster Mitigation Agency said more than 3,600 fires had been detected on Sumatra and Borneo islands by weather satellites, leading to very poor air quality in six provinces with a combined population of more than 23 million.
Nearly every year, forest fires spread health-damaging haze across the country and into neighboring Malaysia and Singapore.
Officials have deployed more than 9,000 people to fight the fires, which have burned more than 400,000 acres in the provinces of Riau, Jambi, South Sumatra, West Kalimantan, Central Kalimantan, and South Kalimantan.
Riau provincial secretary Ahmad Syah Harofie said air pollution had hit hazardous levels in the provincial capital, Pekanbaru, and was very unhealthy in many other areas. Several thousand schools in the capital and three other cities and districts have been closed since Tuesday.
He said nearly 300,000 people in the province have suffered respiratory illnesses since January, when it and the five other provinces declared states of emergency due to the forest fires.
The fires burned parts of Tesso Nilo National Park in Riau, home to about 140 endangered wild elephants, said Edward Sanger, the local disaster agency spokesman.
Thousands of Muslims, many wearing face masks to protest themselves from the smoke, joined mass prayers for rain in Pekanbaru.
The haze is an annual problem for Southeast Asia. Record Indonesian forest fires in 2015 spread haze across a swath of Southeast Asia, and, according to a study by Harvard and Columbia universities, hastened 100,000 deaths.
The fires are often started to clear land for planting. Many areas of Indonesia are prone to rapid burning because of the draining of swampy peatland forests for pulp wood and palm oil plantations.