Indonesia's environment ministry denied accusations that forest fires in Sumatra and its portion of Borneo island, which have blanketed some of its cities with thick haze, have also affected air quality in neighbouring Malaysia.

Malaysia on Friday warned residents of high pollution levels in most areas on the west coast of Peninsular Malaysia and the western Borneo region of Sarawak, blaming trans-boundary haze from Indonesia, its Department of Environment said in a statement.

Indonesia's Environment Minister Siti Nurbaya Bakar responded by saying Jakarta has not detected any travelling haze from Indonesia to neighbouring countries.

"We continue to follow up any development and there is no trans-boundary haze to Malaysia," she said in a statement.

At the moment, Indonesia is focusing on quelling forest fires in some provinces in Sumatra and Borneo with water bombing from helicopters, the minister added.

As well as maritime boundaries, Malaysia shares a land border with Indonesia on Borneo island.

Malaysia has not filed a diplomatic complaint from the haze, Indonesia's foreign ministry spokesperson said.

Indonesia's dry season this year is its most severe since 2019 due to the impact of the El Nino weather pattern.

While forest fires are typically started by farmers to clear land for plantations, authorities say putting out fires this year has been harder due to El Nino.

More than 267,900 hectares (661,995.3 acres) of forests have been burned so far this year, bigger than a total of 204,894 hectares for all of 2022, according to the environment ministry's data.

This has brought haze into several cities in Sumatra and Borneo.

Some areas in Central Kalimantan, Borneo, reported visibility of less than 10 metres (33 feet), state news agency Antara reported.

Authorities ordered remote learning for students in Palembang and Jambi cities in southern Sumatra starting this week due to the severity of pollution, local media reported.