An unannounced inspection by officials from China’s top environment watchdog at a factory in eastern China ended with an unexpected turn of events for all involved, as inspectors were obstructed from performing their duties and later blocked from leaving.

The incident happened on Sunday at a furnace maker in Jinan City, Shandong province, called Shandong Lüjie Environmental Protection Energy Saving Technology Co. Ltd. A manager identified by his surname, Wang, had stopped the team from doing their work, citing “problematic” government identification cards, according to a statement on the Weibo microblog of the Ministry of Environmental Protection (MEP).

Wang later locked an exit to the factory and prevented the team from leaving for more than an hour until police arrived at the scene.

During their inspection, the MEP’s team found several violations of environmental standards. Photos published by the ministry show parts of the factory in a dusty and dilapidated state. Following the incident, authorities suspended work at the factory and dismantled coal-fired boilers they said were operating illegally, pending further investigation.

The Jinan government has condemned the factory manager’s actions as “vicious,” and police have detained two people, including the manager, for their involvement in “illegal activities.” The government also directed all of its departments to cooperate fully with the ministry’s inspection teams.

In a separate recent incident at a manufacturing company in northern China’s Hebei province, an MEP inspection team had their identification cards forcibly confiscated. Authorities detained two suspects following the incident.

The Ministry of Environmental Protection announced in late 2015 that it would conduct spot checks on companies and local governments. In 2016, more than 6,400 people were disciplined as a result of such checks.

Earlier this year, the ministry published a list of companies that had not complied with anti-pollution measures. Additionally, in a bid to make officials more accountable, it also recently started naming and shaming city governments.

In Shanghai, inspectors found the city’s water was of poor quality, and said it was in part caused by illegally dumped trash and landfills polluting water sources. And in Beijing, officials were admonished for blaming the city’s poor air and water quality on pollution from neighboring regions.

Contributions: Lin Qiqing; editor: Kevin Schoenmakers.

(Officials supervise an act of restitution at Lüjie Environmental Technology Co. Ltd. in Jinan, Shandong province, April 17, 2017. Zhang Jiaran/Sixth Tone)