Wen has promised tougher reforms to curb abuse of power, The Guardian reported Sunday.
In an article for his Communist Party's Seeking Truth magazine, Wen said regional governments that allowed "important cases" of corruption or failed to act quickly would be held responsible, adding that governments should quickly investigate claims of corruption by the people and the media.
The crackdown came as an attempt to quell political fallout coming from the suspension former Chongqing party chief Bo, The Guardian said.
Bo's wife and a family employee have been detained on suspicion of murdering Neil Heywood, a British businessman found dead in Chongqing city. Bo may face charges in the case for possible breaches of law and has been suspended from his party post pending an investigation.
"I think this is a very serious legitimacy crisis for the party," said Patricia Thornton, lecturer in politics of China at the University of Oxford. "As more details of the case come out, I think it will be very, very difficult to sustain that."