(Corrects paragraph 12 to clarify that Malaysia's Sarawak borders Indonesia on Borneo island)
JAKARTA, Aug 11 (Reuters) - Indonesia has stepped up efforts to contain forest and land fires across six priority provinces, deploying cloud-seeding aircraft to induce rain as authorities seek to slow the haze now spreading across the region, officials said.
Indonesia is facing a longer and more severe dry season this year as El Nino intensifies, raising the risk of drought, forest fires and air pollution.
Forestry Ministry data showed that 107,465 hectares (265,552 acres) of land were hit by fires from January to June, a 110% increase compared with the same period in 2023, when El Nino last affected Indonesia.
"We are on alert because the weather conditions really make it possible for these fires to become larger," chief security minister Djamari Chaniago told reporters on Monday.
He said there might be signs that El Nino had already reached its most intense level in Indonesia.
The government has identified the six priority provinces as Riau, Jambi and South Sumatra on Sumatra island, as well as West Kalimantan, Central Kalimantan, and South Kalimantan on Borneo island.
Fires have also struck other provinces on the islands of Java, Papua, and Nusa Tenggara.
Classes for all students have been moved online in Pontianak, capital of West Kalimantan, after a decline in air quality caused by the haze, the city's mayor said.
Djamari said 43 helicopters and 15 fixed-wing aircraft have been deployed to put out the fires.
Authorities have also conducted cloud seeding operations, shooting salt flares to stimulate rainfall, but Djamari said the operations are challenging because of the scarcity of rain clouds.
"That is why we closely monitor even small changes in the weather. Whenever something is likely to produce rain clouds, we immediately carry (cloud seeding operations) out," he said.
On Tuesday, 11 areas in Malaysia's Sarawak state, which shares a border with Indonesia on Borneo island, recorded unhealthy air quality levels, according to data from Malaysia's environmental department.
Sarawak's education department has also instructed schools to suspend outdoor activities when temperatures become too high or air quality index readings exceed 100.
On Java island, a fire in Mount Bromo national park in East Java province that damaged at least 899 hectares of land has now mostly been extinguished, head of local disaster mitigation agency Gatot Soebroto told Reuters.
More than 150 personnel were still being deployed on Tuesday to put out the remaining fire, which covered at least two hectares.
(Reporting by Ananda Teresia in Jakarta and Rozanna Latiff in Kuala Lumpur; editing by David Stanway)
