BEIJING — China’s environmental watchdog held 900 officials accountable for allowing encroachment into natural preservation areas in what is considered the country’s most rigorous ever campaign against such violations.

Of the officials punished, six were at bureau-director level and 150 at division-head level, said Cui Shuhong, an official of the Ministry of Ecology and Environment (MEE), at a press briefing on sept 29.

More than 1,800 businesses involved were closed or saw operation suspension, and illegal buildings with a combined area of 19 million square meters were removed.

“The campaign, called Green Shield 2018, aims to crack down on all kinds of illegal activities in nature reserves and safeguard national ecological security,” Cui said.

The central government initiated the environmental inspection in March to restore the environment in protection zones under threat from human activity.

China started establishing nature reserves in 1956 and now has 2,750 covering a total of 147.33 million hectares, accounting for 14.88 percent of the national land area. But some have been disrupted by travel, coal mining and factories.

“A number of violations were found in the inspection,” Cui said, stressing that the main cause was local authorities not putting enough emphasis on the matter. “Some even gave greenlights to developments that would occupy nature reserves, and only took perfunctory action.”

“The MEE will push for rectification of problems found during the inspection and supervise the implementation of local authorities,” Cui said, adding that violators would be responsible for correcting the damaged environment.