Aerial footage captured from a helicopter shows the shocking levels of pollution in Bangkok, Thailand, on Saturday afternoon.

The cloud of haze from car exhaust fumes, building construction and smoke from agricultural burning has shrouded the capital city in recent weeks as the annual smog season begins.

The levels of harmful PM 2.5 particles in the air have reached critically high levels. Health experts say they cause deadly illnesses such as cancer, emphysema, bronchitis, obesity and others.

Government ministers in Thailand and the surrounding countries have been unable to control the issue.

Air quality monitors recorded debilitating high levels of haze every year from November to April - making many cities in Thailand among the worst in the world alongside Delhi.