Islamic authorities in Malaysia seized 321 Bibles from a Christian group because they used the word Allah to refer to God, signalling growing intolerance that may inflame ethnic and religious tension in the Southeast Asian country.

The raid, which took place Thursday in capital Kuala Lumpur, comes after a Malaysian court in October ruled that the Arabic word was exclusive to Muslims, most of whom are ethnic Malays, the largest ethnic group in the country alongside sizable Christian, Hindu and Buddhist minorities.

That ruling then overturned a court decision that allowed a Roman Catholic newspaper printed in Malay, the country's national language, to use Allah.

The change has heightened concern that religious authorities, which issue rulings for Muslims and operate alongside civil courts, now have more legal muscle.

'Allah' controversy called a diversion

Analysts say new rulings that affect non-Muslims could be a way of deflecting anger against Prime Minister Najib Razak's government from poor Malay Muslims over subsidy cuts likely to force up electricity, gas and sugar prices.

On Thursday, the top Islamic authority in the richest and most populous state of Selangor seized the Malay-language Bibles from the Bible Society. The society said authority officials escorted two of its officials to a police station to make statements after which they were released on bail.

"We were told that we were under investigation for breaking a Selangor state law banning non-Muslims from using the word Allah," said Bible Society of Malaysia chairman Lee Min Choon.

The raid is a marked escalation from the occasional seizure at border checkpoints of Bibles imported from Indonesia. It was the first time Islamic authorities have entered premises belonging to a Christian organization to carry out a raid.

Christians from Malaysia's rural states of Sabah and Sarawak in Borneo, who have used the word Allah for centuries, have moved in droves to Selangor and other parts of peninsular Malaysia in recent years to look for work.

No unauthorized use of 'Allah'

The main political party within Najib's ruling coalition, the United Malays National Organization, said its Selangor members would protest at all churches in the state on Sunday against unauthorized use of the word Allah.

"There are laws in Selangor and there was a decree by his Royal Highness the Sultan. So what they are doing is carrying out the Sultan's decree," Deputy Prime Minister and UMNO Deputy President Muhyiddin Yassin was quoted by media as saying.

"They are not doing anything against the law."

The Sultan of Selangor, one of nine sultans who serve in turn as titular Malaysian head of state, decreed last year that non-Muslims must refrain from using Allah in Bibles. He asked Muslims to unite against "bad elements" that misuse the word.

The increasingly assertive stand by holders of the largely ceremonial office show that Muslim leaders have become increasingly vocal about their role in defending Islam.

In 2010, arsonists firebombed several churches over the initial ruling that allowed the Catholic newspaper to use the Arabic word. Two Malay men were found guilty for setting fire to one of the churches.