See how Bangkok fights pollution with water cannon

The Thai capital fired water cannon into the hot tropical air and hosed down streets as authorities handed out masks in a bid to combat air pollution in one of the world's most visited cities which has been blanketed by smog since Saturday.

The level of hazardous dust particles known as PM 2.5 has exceeded the safe level in 30 of 50 Bangkok's districts for days, Bangkok Governor Aswin Kwanmuang told reporters.

Thailand is also set to deploy rainmaking planes to seed clouds in an effort to tackle the pall of pollution that has shrouded the capital in recent weeks.

The weather modification technique involves dispersing chemicals into the air to aid cloud condensation, which should in theory result in rain.

(In pic: A Royal Thai Air Force BT-67 plane sprays 800 gallons (3,000 liters) of water hoping to control heavy smog Bangkok)

Pollution in Bangkok has reached unhealthy levels before, usually during the dry season between January and March, but it doesn't normally hang around too long.

Thai authorities vowed to keep fighting.

Many shops have ran out of masks because of high demand.

The Department of Pollution Control says diesel fumes from cars contribute 50-60 percent of the pollution while burning rubbish and crops attributed about 35 percent.

The government has banned large trucks from entering downtown Bangkok during the rush hours, while police have vowed to enforce the law on emission controls.

Public discontent has surfaced on Thai social media and television, with pollution-related hashtags trending and TV hosts advising viewers on the types of face masks they should wear.

Air Visual, an independent online air quality index (AQI) monitor, pegged Bangkok at "unhealthy" levels measuring 156 AQI on Monday -- though numbers have often crept higher in the last two months.