The Guangdong provincial department of public security is urging local residents to actively tip off police and cooperate in fighting illegal cult activities in the southern province.
Residents should not trust rumors that doomsday has come, police said on their micro blog on Dec 19.
In Guangdong, the cults called themselves "shijijiao", but are actually a branch of the "Almighty God" cult, which has developed around the country.
Police have so far detained 500 people, including 400 members from the "Almighty God" cult nationwide, for spreading rumors.
In Foshan, a city in the Pearl River Delta, police have investigated seven cases involving the cult. Thirty-seven suspects have been detained for further investigation.
Guangdong police said that many illegal rallies of members from the "shijijiao" or "Almighty God" cult have recently been reported in some cities, particularly in the zones between urban and rural areas in Guangdong, which borders the Hong Kong and Macao special administrative regions.
They spread rumors that doomsday is drawing near and urge locals to hand over their property to the cult to ensure its safety, police said.
"The cult's illegal activities have seriously breached social management and disturbed the public order," police said.
Police have promised to take a firm stance in investigating and fighting illegal activities of the cults.
The "Almighty God" cult, which is like a pyramid sales organization, is believed to have been established in Henan province in 1990. It has introduced tight rules and regulations.
"All the members of the cult use only aliases when they rally and communicate, and none of them are allowed to bring mobile phones and other communication tools when they rally," police said.
