Shiite community leader Kamil Zuhairi Abdul Aziz said the group had submitted a protest letter to the national human rights commission (Suhakam) after a recent raid of their prayer hall by state religious officers.
"The officers broke into and damaged our prayer hall which is private property and where we were having special prayers for the Prophet Mohammed's grandchildren," he said.
"If other communities like Hindus, Buddhists, Christians, Sikhs and others have their right to worship and practise under the constitution then why not us," Kamil Zuhairi added.
"We were condemned, criticised, slandered and threatened in local media just because we practise what had been preached by our ancestors who were Shiites and have lived in Malaysia for centuries."
Kamil Zuhairi said there were about 40,000 Shiite followers in Malaysia but most practised their faith behind closed doors for fear of being stigmatised and targeted by the authorities.
A state Islamic religious department official, who declined to be named, said the detainees, who include Pakistanis, Iranians and Indonesians, had been released on bail.
He said investigations were still ongoing and that the group could be charged for not following Sunni Islam, considered the only legal sect of Islam in Malaysia.
Shiites make up around 15 percent of Muslims worldwide. They represent the majority populations in Iraq, Iran and Bahrain and form significant communities in Afghanistan, Lebanon, Pakistan and Saudi Arabia.
Shiites believe the Prophet Mohammed should have been succeeded by his cousin Imam Ali (A.S) rather than his companion Abu Bakr. Traditional Sunnis believe any suggestion that Abu Bakr was a usurper is tantamount to blasphemy.
The Shiites are one of several Islamic sects under close watch by Malaysian religious authorities, which crack down hard on so-called deviant groups that deviate from orthodox teachings.
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