Beijing issues
uildings are seen during a moderately polluted day in Nanjing, Jiangsu Province, China, April 19, 2016. Reuters

A red alert has been issued in Beijing after air pollution in the city worsened to severe levels. The environmental protection bureau said on its official Weibo account the alert will remain in place for five days starting from Friday to Dec 21.

The post cited forecasts from the China Environmental Monitoring Centre and said the smog was created due to an accumulation of massive air pollution in Beijing and its surrounding areas, including Tianjin city and Hebei, Shandong and Hunan provinces.

Last year in December, Beijing issued a red alert for the first time. The authorities asked the schools to remain closed and halted construction in the city temporarily.

Since then, the government has been pulling the measures. In February, it raised the threshold of issuance to a higher average daily air quality index reading.

Beijing government also introduced a colour-graded warning system of alerts in 2015 as a part of crackdown efforts on environmental degradation following decades of unbridled economic growth.