China arrested 186 people on charges of environmental pollution in 2013 in a total of 109 cases, environment minister Zhou Shengxian announced on Thursday.

He did not reveal how many were convicted.

Environmental authorities shut down more than 3,500 companies and workshops in a nationwide campaign last year, uncovering 6,499 cases involving environmental problems, he said.

A total of 706 cases related to environmental rule violations were transferred to police last year, more than the total of the previous 10 years combined, according to Zhou.

This year's campaign will focus on inspections to prevent and control air pollution as well as treatment of water pollution caused by high-polluting industries, such as heavy metals and pharmaceuticals, Zhou said.

The ministry has suspended environmental approvals for new construction projects with chemical oxygen demand and ammonia nitrogen emissions in four cities -- Jixi, Lianyungang, Yueyang and Yulin -- and suspended approvals for new construction projects with sulfur dioxide and nitrogen oxide emissions in Shantou City, as the five failed the annual evaluation on pollutant emission reduction for 2013, according to Zhou.

Last year, the country's two oil giants, the China National Petroleum Corporation (CNPC) and the China Petroleum and Chemical Corporation (Sinopec), were also banned from environmental approvals for new refining projects due to their failure in the evaluation.

Another 19 companies were fined for weak desulfurization.