Beijing was again shrouded in smog today, prompting a second wave of emergency measures from the city government designed to tackle the capital’s crippling air pollution.

State news agency Xinhua reported officials held an urgent meeting today to discuss “emergency work” for limiting the smog and confirmed that 103 polluting factories have been ordered to close until Thursday at the earliest.

The agency also reported that “all counties, departments, businesses and institutions” have been ordered to suspend the service of official vehicles.

The latest steps came as Beijing’s pollution spiked for the second time in as many weeks, with the US embassy reporting that its air pollution index score had reached 517 - a level described as “beyond index”.

Residents reported that visibility was down to 100 metres in some areas and Air China confirmed that 14 flights had been cancelled at the city’s airport.

Today’s wave of factory shutdowns and travel restrictions follow similar moves last week, which also saw Mayor Wang Ashun vow to take 180,000 older cars off the roads and take measures to tackle “excessive” growth in car ownership.