Recently in Shizuishan, Cai saw cult members using a loudspeaker at a public square to spread doomsday rumors and claiming that only their followers could be saved.

Many of them are middle-aged women, Cai said, adding that they come out in the evening, offering free books about Almighty God.

Each of them is said to have converted five or six new members, Cai said.

"They told people not to read the Bible anymore, claiming the Bible is a riddle, and their books provide the solution," Cai said.

The residents are highly impressionable. Although they know little about true Christian beliefs, they consider themselves superior to nonbelievers. Some church-goers took everything the cult members threw at them: stop reading the Bible and pick up the new "godly" books instead, Cai said.

She and more than 100 Christian volunteers will conduct door-to-door visits to raise awareness of the 3,000 believers in her church and collect cult publications.

The cult reportedly started in 1990 in Central China's Henan province. It disseminated the Mayan doomsday prophecy about three days of darkness starting on Friday.