Polluting companies have been fined 420 million yuan ($61.8 million) in the first four months of this year, 1.7 times the amount of the same period last year, the Ministry of Environmental Protection said on Thursday. 

Environment bureaus around the country have taken tougher measures to punish violators, it said, adding that fines reached 145 million yuan in April, a 73 percent increase on the previous month.

More than 1,900 polluting companies were also shut down or ordered to suspend production in the first four months, a 317 percent increase on the same period of last year, the ministry said. 

Administrative detentions of up to 15 days were also handed out in 1,955 cases, an increase of 201 percent year-on-year. 

However, the ministry highlighted three cities — Zhangjiakou and Chengde, of Hebei province, and Liuzhou of the Guangxi Zhuang autonomous region — for not having any businesses that were fined for polluting or shut down in the first four months of the year.