Beijing has set an air quality target for 2017 that is over double the World Health Organisation (WHO) standard.

Beijing’s mayor Cai Qi announced reforms this week as hazardous air pollution continues to plague the Chinese capital.

“We will work hard to keep PM2.5 at an annual average of around 60 micrograms per cubic metre,” Mayor Cai Qi said.

PM2.5 is a classification for air particles small enough to pass through human lungs.

The WHO’s acceptable PM2.5 annual average is 20-25 micrograms per cubic metre.

The municipal government says Beijing’s air quality improved 9.9 per cent in 2016, but that PM2.5 was at an annual average of 73.

Smog continues to engulf Beijing and large areas in the north and centre of China, often disrupting flights, port operations and schools.

Beijing says it will establish a specialised police force to deal with environmental offences as it struggles to improve air quality and crack down on polluters.