"Of the total number, 963 were found in Riau Province. The number is significantly up from those on the previous day," Sugarin, the head of the Pekanbaru meteorological, climatology and geophysics agency, said here on Saturday.
The NOAA 18 satellite, however, detected only 138 hotspots across Sumatra on Friday, including 70 in Riau province, according to the Riau disaster mitigation office (BPBD).
During February 2014, the NOAA 8 satellite revealed 2,208 hotspots on Sumatra Island, including 1,272 in Riau Province.
In Riau, hotspots were found in Bengkalis (312), Pelalawan (198 titik), Dumai (174), Siak (147), Indragiri Hilir (130), Rokan Hilir (110), Meranti (91), Kampar (49), Indragiri Hulu (29), and Kuantan Singingi (16).
Chief of the National Disaster Mitigation Agency (BNPB) Syamsul Maarif stated that some 99 percent of forest and plantation fires in Sumatra and Kalimantan were deliberately set.
"There should be sanctions to stop recurrences. Slash-and-burn farming methods exist in Sumatra and Kalimantan, but the most important thing is that they should be controlled," Maarif noted in a statement on Feb. 28.
According to Maarif, the Indonesian police have named 23 suspects in Riau and 16 in Central Kalimantan, who allegedly set the fires.
"There are several factors behind their decision to set fires in plantation and forest areas, such as economic, social and cultural factors," he explained.
The hotspots were also detected in other districts of Riau, including Indragiri Hulu (29), and Rokan Hulu (14), as well as Riaus capital of Pekanbaru (two).
On February 28, the Riau provincial police announced that 40 individuals have been named as suspects in forest and plantations fires in several districts and cities.
"All of them have been detained, after being identified as suspects, for allegedly setting fires during the past several weeks," said Senior Commissioner Estuning of the Riau police plantation fire task force.
The suspects were all individuals, she added. "The cases allegedly involving companies are still under investigation," she pointed out.