Two policemen have been shot and two more stabbed during a raid on an Islamic sect engaged in wife-swapping in the northern Nigerian state of Kebbi, authorities say.
Sect members armed with guns, daggers and bows and arrows attacked police and government workers who were sent to destroy the group's base in the state capital Birnin-Kebbi.
The raid on Wednesday morning sparked an intense hour-long battle, police said.
"They were debasing the morality of our community and the teachings of Islam by prostituting their wives in such a way," said Kebbi State police spokesman Ibrahim Sa'ad Muhammed on Thursday.
"They attacked the workers, and the police called in reinforcements. An hour-long battle commenced, two of our men were shot and two stabbed. Some of the members of the sect were also injured in the fight," he added.
Police said the Shi'ite sect had refused offers of dialogue and orders from the state government to vacate its premises after residents complained the sect was an insult to Islam.
The group had called their base the Ka'bah, named after the holiest shrine in Mecca, Saudi Arabia, the birthplace of Islam.
Police arrested about 20 sect members and sent patrols to hunt down hundreds of others who escaped, said Muhammed.
Kebbi is one of 12 northern Nigerian states to have declared Muslim sharia Islamic law in 2000.