A fire engulfing two mountains in northern Thailand neared residential areas today as it continues to burn.

The blaze, reportedly sparked by lightning during a summer storm, has been ripping through parts of the Khao Chaphlu and Khao Laem mountains in Nakhon Nayok province since Tuesday evening.

As of March 31, more than 300 acres of forest has been destroyed, with the fire inching closer towards communities in the nearby Muang district.

The Royal Thai Army, Department of Disaster Prevention and Mitigation, and the Ministry of Natural Resources and Environment, have deployed helicopters and cloud-seeding jets to bring rain and try to prevent the fire from spreading on March 30.

However, aerial operations were suspended at night due to hazardous conditions before resuming this morning.

Authorities fear that high winds may further intensify the blaze and spread it towards the Khao Yai National Park a few kilometres away.

Thailand's Meteorological Department warned that the fire may cause severe air pollution in Bangkok and surrounding provinces if not contained in three to four days.