The religious authorities said they will crack down on four sects deemed "deviant" in Selangor after they ignored calls to stop their activities.

The four sects have been operating secretly after they were gazetted as deviant by the fatwa council, said a senior state religious official.

"They seem to be defying the authorities and remain unyielding, while some among them are on a membership drive," Abdul Rahman Palil was quoted as saying by the state Bernama news agency.

"Some have put up huge buildings and violate laws at will," he said.

Sect members that are detained will be sent to a rehabilitation centre in the state's north and they will be prosecuted if they persist with their activities, he said.

He did not reveal what specifically these sects had done to be branded deviant. However the issue of religion in mainly Muslim Malaysia is sensitive, and the government is always on the lookout for Muslims who deviate from accepted Islamic practice in what it calls deviant sects.

Authorities taking part in the crackdown on the sects, whose members number 500 in total, were the Selangor Islamic Affairs Department, local area authorities and police.