China is stepping up a crackdown on "evil" cults, detaining more than 400 members of the "Almighty God" doomsday sect in just one province, with scores of others held nationwide, state press said Tuesday.

The Christian-inspired group has been accused of spreading doomsday rumours apparently linked to the ancient Mayan calendar and urging followers to fight a "decisive battle" to slay the "red dragon" of communism, reports said.

More than 400 followers of the sect, also known as "Oriental Lightning", have been detained in the remote northwestern province of Qinghai since last week with large amounts of printed and digital materials confiscated, state broadcaster China Central Television (CCTV) said.

"The numbers you have seen in the media reports are about right," a government spokesman in Qinghai told AFP by phone, refusing further comment.

On Monday, Xinhua news agency said 37 members of "Almighty God" had been detained in Qinghai, while 56 others had been detained around China for prophesying the end of the world on December 21, when the Mayan Long Count calendar expires.

"The investigation into the 'Almighty God' evil sect forms an important aspect of our maintenance stability work and we will closely link it up with our anti-self-immolation fight," CCTV cited Qinghai police as saying.

The comment was a reference to nearly 100 Tibetans setting themselves on fire since 2009 in protest at China's rule of its Tibetan-inhabited regions, which include Qinghai.

China's ruling Communist Party does not tolerate challenges to its authority and has brutally cracked down on religious groups that refuse to toe the party line, including the Buddhist-inspired Falun Gong, which was banned in the late 1990s.

China has a long history of religiously-inspired anti-government movements, most notably the nineteenth century "Taiping Heavenly Kingdom", led by a Christian convert who gathered hundreds of thousands of followers in an attempt to overthrow the emperor.