BEIJING (Reuters) - Residents of China’s capital awoke on Saturday to dense, choking smog after many set off a barrage of fireworks overnight to ring in the Lunar New Year, despite limits and public admonitions against such displays in the congested city.

The Beijing Municipal Environmental Protection Bureau said harmful particulate matter in the air had hit the second-highest level in five years by Saturday morning, the state-owned China News Service reported.

Beijing launched a “war against pollution” in 2014 as part of a central government promise to reverse damage done by decades of breakneck growth and strengthen powers to shut down and punish polluters. Efforts to clean up the skies in the industrial heartland around Beijing are being thwarted by coal-burning industry and indoor heating, which increases during China’s winter months.

Public health concerns over air pollution have grown and the government has found no source of pollution too small to ignore. They have even taken on outdoor food vendors in recent years, as well as the annual battle against China’s long tradition of lighting fireworks to celebrate the Lunar New Year.

“In setting off fireworks, be conscious of ‘setting off the (pollution) index’,” read an editorial on Saturday in the People’s Daily newspaper, the Communist Party mouthpiece.

Hundreds of millions of people criss-cross China to visit family and friends during the Lunar New Year period, with the government predicting up to 3 billion trips.

In Beijing, efforts to ease smog included neighborhood postings asking residents not to light fireworks, fewer approvals for firework stalls and officials being warned to lead by example and abstain from the pyrotechnics. [nL4N1FH149]

Slideshow ( 2 images )

Although state-owned Xinhua reported that purchases of fireworks fell 4.9 percent in Beijing this year, the measures weren’t enough to avoid a spike in pollution from healthy to hazardous levels in a matter of hours.

Beijing’s level of PM2.5, a measure of small particulate matter particularly damaging to health, peaked at 647 micrograms per cubic meter early on Saturday, the national Ministry of Environmental Protection said in a statement on its website.

That was well beyond the upper limit of 500 on China’s air quality index and double the threshold considered hazardous.

The greater region of Beijing, the nearby port city of Tianjin and surrounding Hebei province surpassed peak levels of PM2.5 in 2016, it said.

In response, many on the streets of Beijing wore masks to welcome the Year of the Rooster, including paramilitary police stationed at Beijing’s Lama Temple and spectators at outdoor performances.

Dispersal of the pollution largely depends on weather conditions, with two cold air fronts likely to help reduce pollution in the Beijing-Tianjin-Hebei Region through to Wednesday, the environmental ministry said, before conditions deteriorate again and potentially lead to another heavy bout of pollution.