BEIJING, Jan. 23 (Xinhua) -- Anti-graft authorities must keep calm and be persistent in the fight against corruption to avoid the resurgence of evil influence, a disciplinary official Sun Zhiyong wrote on Thursday.

Great achievements have been achieved in the past two years, and the "visible," "touchable" changes are dispersing the "smog hanging over the people's minds," Sun, an official with the Communist Party of China's (CPC's) Central Commission for Discipline Inspection said on the commission's website.

However, the root breeding the corruption has not been pulled out and some untouched corrupt cadres are still struggling like beasts at bay, Sun said.

Defending the victory is harder than winning it and we must progress with firm steps and grasp tightly the sharp sword in the lasting war against corruption, he wrote.

According to another article published on CCDI's website Friday, Sun was also calling for more supervision over the disciplinary and law enforcement staff, acknowledging that corruption problems also exist in corruption-fighting authorities.

The CPC ordered a wash of the "stains" left by ousted former state leader Zhou Yongkang at a conference Wednesday, as "Zhou severely harmed the Party and the country, leading a number of officials astray."

The conference described Zhou "a former senior leader who blatantly traded power for money and sex."

Zhou, former member of the Standing Committee of the Political Bureau of the CPC Central Committee, was arrested and expelled from the CPC in December for Party rules violations and alleged crimes.