Chongqing police have raided two illegal radio stations and confiscated their transmitters, antennas and computers, the Xinhua News Agency reported on Monday.

As part of an ongoing campaign launched in April, city police located and seized illegal transmitters in Jiangbei and Yuzhong districts, the report said, but did not say if anyone had been arrested in the raids.

"The city is carrying on its joint campaign on illegal radio," Chongqing Culture Radio and Television Bureau staff member Li Xiaopeng told the Global Times on Tuesday.

Li's bureau, Chongqing Radio Management Committee, and local police have all been involved in tackling the illegal broadcasts.

Li added no more details to the Xinhua story reported on Monday, but his bureau's own website said the hit had occurred between September 26 and 27.

City residents had first tuned into obscene adverts for sexual performance drugs on their radios in late March, Zhang Xueming, a senior official from the city's radio management committee, told the Chongqing Evening Post in April.

Authorities began investigating the case after receiving more than 100 reports of illegal transmissions, Zhang told the paper. The drugs advertised had been expensive, several hundred yuan each, and a few citizens had bought them and felt cheated.

From April to September, Chongqing authorities have launched four raids, arresting one suspect and confiscating six transmitters, six antennas and six computers.