Malaysian Prime Minister Mahathir Mohamad will write a letter to Indonesian President Joko Widodo about the ongoing transboundary haze, as air quality continues to worsen in his country.
Malaysia's Minister of Energy, Science, Technology, Environment and Climate Change Yeo Bee Yin said: "I spoke to Prime Minister and he agreed to write a letter to President Jokowi to draw his attention on the issue of haze crossing borders."
Mr Joko is popularly known as Jokowi.
Speaking to reporters in Johor, Ms Yeo defended her remarks on Facebook citing data from the Asean Specialised Meteorological Centre (ASMC) which showed that the haze impacting parts of Malaysia originated in Indonesia.
"As environment minister, I hope the Indonesian government will increase their machinery to battle forest fires in Kalimantan and Sumatra," she said. "We hope Indonesia will be responsible for the fires in their own country."
The ongoing haze led to a diplomatic dispute after Indonesia's Environment and Forestry Minister Siti Nurbaya Bakar told Indonesian local media that Malaysia had sent a protest letter accusing the country of causing the haze.
Malaysia's Ambassador to Indonesia Zainal Abidin Bakar clarified with national newswire Bernama that it was not a protest letter, but an offer to assist with combating forest and agricultural fires in Indonesia.
Ms Siti Nurbaya also denied Ms Yeo's statements that the haze had come from Indonesia, eliciting a response on Ms Yeo's Facebook page on Wednesday night.
"Let the data speak for itself," Ms Yeo wrote. "As for her claim that the haze is from Sarawak, just look at the wind direction. How is it logically possible?" Her question was accompanied by a link to the ASMC website showing its forecast for prevailing winds from the south-east or south-west.
The highest Air Pollution Index reading recorded yesterday, in Klang, Selangor.
Yesterday, the number of hot spots in Kalimantan rose to 1,188 from the 474 recorded the day before, according to ASMC, a collaboration between member countries' meteorological services. Sumatra had 431, up from 387.
In Malaysia, five hot spots were detected, down from seven.
The highest Air Pollution Index (API) reading recorded yesterday was in Klang, Selangor, in an area called Johan Setia, where the API reached 213, in a range classified as very unhealthy. Five schools in the area were ordered to close yesterday, and 29 schools in Selangor have been ordered to close today.
Nationwide, there were over a dozen locations with API readings at unhealthy levels of 101 to 200.
Indonesia's Meteorology, Climatology and Geophysics Agency (BMKG) maintained its claim that forest fires in Indonesia were not the main culprit of the haze blanketing parts of Malaysia.
Yesterday, its chief, Dr Dwikorita Karnawati, said smoke from Sumatra had been detected entering Malaysia at 8am on Wednesday, but had stopped by 4pm. Since then, satellite data showed no haze from Sumatra crossing the Strait of Malacca into Malaysia, she added.
She said fires have been detected in Thailand, the Philippines, Papua New Guinea, Vietnam and Timor-Leste since the start of this month.
BMKG predicts that hot spots and haze may persist until the middle of next month due to the dry season in Sumatra and Kalimantan.
Smoke continues to thicken and visibility has plummeted in many parts of Indonesia. Yesterday, some flights out of Banjarmasin, the capital of South Kalimantan, and Pangkalan Bun in Central Kalimantan were delayed for hours due to smoke-clogged skies.
Mr Hendi, who works for low-cost airline Wings Air and goes by one name, said: "This morning, haze was so thick at the airport in Pangkalan Bun that visibility was just 200m."
More than a thousand students held an outdoor protest outside the office of the Riau governor yesterday, with three having to be rushed to the hospital because of breathing problems.