The police in a county in Shandong province are looking into a case in which at least five middle-school girls were allegedly sexually assaulted by gang members.

The teenagers, aged 11 to 15 years, were forced to have sexual intercourse with men who regularly parked limousines in front of their middle school in Dongping county, according to a report in Beijing News.

The victims' families are accusing government officials of covering up the crimes by interfering with the police investigation, the report said.

Zhang Lizhi, head of the Baojiudian township police station, told the newspaper that one of the suspects, Huang Dewu, had already been detained on an allegation of arson.

Huang admitted that he and some other suspects had sex with the schoolgirls, but claimed that the girls acted willingly, the authorities said.

It's difficult to collect sufficient evidence to accuse the suspects of rape, Zhang was quoted as saying, and the case is still under investigation.

Some of the victims' parents feel humiliated and are reluctant to admit that their daughters were sexually assaulted, the report said.