And there are more bad news - the helicopter carrying out the water bombing had to halt its operations after the equipment broke down due to the extra-heavy workload.
The helicopter performed over 40 sorties on Thursday.
Sarawak Assistant Minister for Communications Datuk Lee Kim Shin told The Star the forest fires have brought smog and ashes to densely-populated residential estates all the way to Miri City.
The air pollution is causing health hazards to thousands of people living along the 30km-length from Miri City to Kuala Baram, he said.
"The Fire Department today carried out 20 sorties of water bombing but still the fires raged on.
"After two days of intensive water bombing, the helicopter's water-bucket is facing technical problems. It has to be flown back to base to repair," Lee, who is Senadin assemblyman, said.
Lee said the authorities must investigate thoroughly how the fires started and if there are people purposely setting fires to clear the land.