JAKARTA (Reuters) – Indonesia on Friday blamed four Malaysian companies, including the world’s biggest producer of sustainable palm oil, for causing some of the forest fires within its borders, in an escalating row between neighbours over regional haze. Malaysia has said Indonesian forest fires are responsible for the smoky haze that has caused air quality to drop to unhealthy levels in certain parts of the country. Indonesia has dismissed those claims, saying fires within Malaysia are causing the pollution. Indonesia’s Environment Minister Siti Nurbaya Bakar on Friday said Malaysia had not painted an objective picture of the fires, which have ripped through parts of Indonesia’s Sumatra and Borneo islands for more than a month. At least four palm oil companies whose land had been sealed off because fires have been spotted were subsidiaries of Malaysian groups, Bakar told Reuters. She named the four as West Kalimantan-based Sime Indo Agro, a unit of Sime Darby Plantation; Sukses Karya Sawit, a unit of IOI Corporation; Rafi Kamajaya Abadi, a unit of TDM Berhad; and Riau-based Adei Plantation and Industry, a unit of Kuala Lumpur Kepong Group. The Indonesian government has said it has sealed off plantations operated by at least 30 companies and brought criminal charges against four of them. Sime Darby is the world’s largest oil palm planter by land size and the largest producer of sustainable palm oil. A spokeswoman for Jakarta-based Minamas Plantation, a Sime Darby unit which runs the group’s Indonesian operations, said it was not aware its plantation had been sealed off and that it was monitoring its lands for hotspots. Sime Darby and IOI both said they were checking their Indonesian operations. Sukses Karya Sawit, Rafi Kamajaya Abadi and Adei Plantation and Industry could not be reached. Kuala Lumpur Kepong and TDM Berhad, which is owned by the Malaysian state of Terengganu, did not reply to requests for comment. Malaysia Environment Minister Yeo Bee Yin told Reuters that Jakarta should take action against those who caused the fires. “Indonesia should take action against the perpetrators of the forest fires, regardless of who they are and without fear or favour, according to the law of the land. Most importantly, the forest fires must be extinguished as soon as possible,” she said. Forest fires have become an almost annual occurrence in Indonesia, especially in dry years, and Indonesia’s neighbours have complained of the thick, choking haze wafting in, raising concern about health and the impact on tourism. Malaysia closed hundreds of schools and sent half a million face masks to Sarawak this week. Air quality in Indonesian towns closest to the fires have risen to hazardous levels and on Wednesday thousands held mass Islamic prayers for rain. ‘MALAYSIA SHOULD BE OBJECTIVE’ Minister Bakar said while smog from fires in Indonesia may have crossed over to Malaysia, fires detected last week in the Malaysian state of Sarawak in Borneo and peninsular Malaysia also contributed to worsening air quality there. “I only asked that they (Malaysians) be objective and sequential in their data analysis,” she told Reuters, responding to Kuala Lumpur’s remarks that it was using recent data from ASEAN Specialised Meteorological Centre. Malaysia’s Yeo in a post on her Facebook page on Thursday evening said Indonesia “should not be in denial” and the data should speak for itself. Yeo said the ASEAN data put the number of hotspots in the Indonesian provinces on Borneo and on Sumatra island at 474 and 387, respectively, versus 7 in Malaysia. She said on Thursday that Prime Minister Mahathir Mohamad would write to Indonesia’s President Joko Widodo to raise concerns about cross-border haze. Bakar said she was not seeking to look for excuses but did not “have time for polemics” and would rather work on putting out fires that she said covered a “huge” area. Jakarta has deployed 46 helicopters for water bombing and cloud seeding, Bakar said.