XINING, Feb. 19 (Xinhua) -- A total of 261 enterprises in northwest China's Qinghai Province were held accountable and punished for illegal activities violating environmental laws in 2018, local authorities said Tuesday.

The provincial bureau of ecology and environment announced that the companies received administrative penalties and were fined 19.6 million yuan (about 2.9 million U. S. dollars).

Seven out of the companies were ordered to close down and 27 were sealed up and distrained. Production of eight companies was limited or suspended. Seven have been transferred to judicial authorities.

The province has suspended the operation of 301 breeding companies, further improving its water environment.

Local authorities also carried out investigations on solid waste, clearing up 331 tonnes of general solid waste and 890,000 cubic meters of industrial residue.

With an average altitude of 3,000 meters, Qinghai is home to headwaters of three major rivers -- the Yellow, the Yangtze and the Lancang (Mekong) rivers.