Chinese authorities have charged 28 people and 15 officials including police are being investigated for corruption two months after a brutal attack on several women in the city of Tangshan that sparked outrage and safety concerns.

The investigation has gone beyond the actual attack to encompass broader allegations of criminal activity and police corruption in the area.

In June, a group of men attacked four women in a barbecue restaurant, after one of the men had his advances rebuffed.

In graphic video footage circulated online, the men threw a chair at the women, and later dragged one of them out before hitting and kicking her and the others who tried to help her, authorities said.

The assault and the public outcry renewed a conversation about misogyny and mistreatment of women in China.

The attackers were suspected to be part of a gang, and local media reported at the time of the attack that the police response had been slow, prompting concerns that corruption was involved.

On Monday, authorities from the Hebei Provincial Commission for Discipline Inspection said they were investigating 15 officials over corruption that involved “evil organisations”, including those associated with the attackers.

Police investigated for abuse of power, bribery

The 15 officials, including the director of Tangshan’s public security bureau and officers from several police stations, are suspected of abuse of power, bribery and other job-related crimes.

Eight of them have been detained during the investigation.

Separately, prosecutors said 28 people, including the men beating up the women in the video, had been charged recently.

At least nine were arrested shortly after the attack.

State broadcaster CCTV reported the charges were laid on Friday.

The 11 offences against them include opening casinos, robbery, assisting in cybercrime activities, picking quarrels and provoking trouble.

Two of the women who were attacked were hospitalised for at least 11 days, while the others had minor injuries.

Prosecutors also dismissed rumours involving the case, including that the four women had been sexually assaulted, pushed off a building or run over by a car, stating that these rumours were proven false after investigation.