A senior Chinese official has called for international cooperation in the country's campaign against online pornography.

"Since the beginning of the crackdown in April, 62 percent of the websites the public has reported to contain obscene materials are overseas Chinese sites, and most of the pornographic movies and images are from outside the border," Cai Mingzhao, deputy director of the State Council's Information Office, told Xinhua on Wednesday.

"Thus, one country's effort is not enough in cracking down on online pornography. It requires the joint efforts of the international community."

Some website owners engage in online pornography simply to make money, Cai noted, but a considerable number deliberately do this "to flood China with pornography".

In cooperation with other government departments, the Information Office has deleted more than 7,000 sexually explicit pictures, 1,300 audio and video clips and 14,000 messages from the Internet since April, according to Cai.