Authorities in China arrested 186 people on environmental pollution grounds last year, the country's environment minister Zhou Shengxian has revealed.

The culprits were detained in a total of 109 cases, Shengxian said, without specifying how many of those arrested were found guilty of violating environmental regulations.

As part of a nationwide campaign carried out in 2013 by local environmental authorities, over 3,500 businesses and workshops were closed after some 6,500 instances of environmental problems were detected. As many as 706 of the cases were referred to the police, which was higher than the number of all environmental rule violations transferred in the previous decade, the minister said.

Environmental authorities will conduct a similar campaign in 2014, with inspections aimed at tackling air pollution and tightening control over water pollution treatment practices in heavy metals, pharmaceuticals and other industries known to have a large ecological footprint.

Last year the environment ministry suspended approvals of environmental impact assessments for construction projects in Jixi, Lianyungang, Yueyang, Yulin and Shantou City following their failure to meet targets to cut pollutant emissions. The country's top state-owned oil firms, China National Petroleum Corporation (CNPC) and the China Petroleum and Chemical Corporation (Sinopec), were also affected, failing to obtain environmental approvals for new refining projects due their high pollution emissions. The ministry fined another 19 firms for poor desulfurization processes.