BEIJING - Police have raided eight gambling dens and one prostitution ring in the city of Sanhe, North China's Hebei province, arresting 285 suspects, the Ministry of Public Security said in a statement released on Tuesday.

More than 400 police were mobilized after receiving tips from local residents regarding crowds of gamblers in video game arcades and prostitution in local clubs and spas.

The ministry did not give further details on the timing of the raid, nor did it provide any information about whether the gambling dens were related to the prostitution ring.

Most of the gamblers are from China's two northern municipalities of Beijing and Tianjin, according to police investigation.

In the statement, the ministry vowed to harshly crack down on the operators of underground workshops, black markets, gambling and prostitution dens and root out their "protective umbrellas."