Malaysia’s ban was issued in 1996 by the National Fatwa Council of top Islamic clerics and seen as unusual in the Muslim world. The council comes under the government’s Islamic Advancement Department, so its decrees are de facto law.

Malaysian religious police raided a three-story shop-house last month and detained more than 100 Shiites who had gathered to mark the death of one of their most beloved saints, Prophet Muhammad’s grandson, who was killed in the year 680.

It was one of the largest such sweeps in years, sparking outrage and fear in the country’s small but growing Shiite community. Some religious scholars see it as a worrying sign that Islamic authorities are becoming more hard-line.

“Malaysia is trying to become a country a la Taliban that only allows one school of thought,” said prominent scholar Asri Zainul Abidin.

Despite its reputation for religious tolerance, Malaysia has been quietly discriminating against its own for years. The government recognizes only the Sunni branch of Islam and prohibits all others including Shiites, the world’s second largest Islamic group.

Shiites face discrimination elsewhere, but Malaysia appears to be the only place that actually outlaws them.

“We are the oppressed people,” said Kamil Zuhairi Abdul Aziz, the Iranian-trained religious leader for the Lovers of the Prophet’s Household, the Shiite group raided by the religious police on Dec. 15.

Kamil estimates there are at least 40,000 Shiites among Malaysia’s 16 million Muslims, though the number could be higher as many conceal their faith to avoid trouble. A few have been detained in the past, and some sent to faith rehabilitation centers, but there is no official data on the number of arrests.