BEIJING - Chinese authorities have announced the closure of 42 websites involved in blackmail cases that saw them pose as accredited journalists capable of disclosing their victims' "negative information."

They were found to have threatened to practice journalism and managed to force many entities and individuals to hand over money, Xinhua was told on Saturday by a source with the State Internet Information Office (SIIO).

The websites, including www.zgzxdcw.com and www.fz-china.com.cn, were operated under false names of government agencies or public welfare institutions and with fabricated press badges.

"Such odious practices have caused serious harm," said an unidentified senior journalism affairs official with the SIIO, who said the closures took place "recently."

Condemning such acts as severe illegalities, the official stressed that one must hold a press card issued by the General Administration of Press and Publication for news reporting.

Those involved will be punished, according to the SIIO.