Melbourne's air quality 'worst in the world' as bushfires continue to burn across Victoria

Authorities warn people to take health precautions as firefighters spend night responding to alarms triggered by smoke haze

Victorians started Tuesday by breathing in the worst air in the world due to smoke blowing down from bushfires in the state's east and New South Wales.

The city centre recorded hazardous levels of fine particles in the air from 12am to 4am and had since been categorised as very poor by the Environmental Protection Authority.