More than 20 Shia Muslims have been arrested by Malaysian authorities in a series of raids over the past few days, which have sparked fears of an upward trend of persecution.

Media reports on Wednesday quoted Kamil Zuhairi, a senior cleric, as saying that police in the central state of Selangor had arrested 22 Shias during a gathering to recite Quran and observe Ashura, which marks the martyrdom anniversary of Imam Hussein, the third Shia Imam and the grandson of Prophet Mohammad (peace be upon him).

Hasan Askari, another cleric, said, “They used violence on us, some of us were handcuffed. They accused us of insulting Islam.”

Authorities in Selangor confirmed the arrests and said the move was because Shia teachings are banned in the state. They say all of those detained have now been released but some expressed fears that they could still face action in court.

On Monday, eight men were detained by religious authorities and police in the southern state of Johor during the Muharram ceremonies at a private residence.

Suhakam, Malaysia’s official human rights commission, has strongly denounced the latest crackdown on Shia Muslims.

“Unless Malaysian authorities, NGOs and civil society respect and tolerate the religious practices of all persons, we cannot truly profess to be a diverse and multi-cultural nation,” it said.

Ahmad Farouk Musa, the founder of rights group the Islamic Renaissance Front, said, “The crackdown on Shias celebrating Ashura must stop. Shias have the right to commemorate Ashura.”

The Human Rights Commission of Malaysia, set up by the government, has received complaints from the Shia minority. The commission, however, has an advisory role.

While the government strives to promote Malaysia as a moderate Muslim nation, analysts say extremist religious authorities are trying to enforce a strict Wahhabi interpretation of Islam, and their power is growing.