The tiny oil-rich Asian nation of Brunei has banned all public Christmas celebrations, from tree lighting to the donning of Santa hats, and threatened offenders with up to five years in prison, The Sydney Morning Herald reports.

The prison term applies to Muslims seen celebrating the Christian holiday and non-Muslims found planning Christmas events. But the country's non-Muslims, who make up around 32 percent of the population, are allowed to celebrate Christmas in their own communities – as long as Muslims aren’t invited.

The ban was first enacted last year to control the act of celebrating Christmas excessively and openly, which could "damage the aqidah (beliefs) of the Muslim community," the Ministry of Religious Affairs said in a statement published in the Brunei Times.

According to the statement, Christmas celebrations violate the penal code prohibiting the propagation of religions other than Islam to Muslims.

"Some may think that it is a frivolous matter and should not be brought up as an issue," a group of local imams told the Borneo Bulletin, the Australian newspaper reports. "We must keep it away as it could affect our Islamic faith."

While Brunei’s rulers do not enforce the harsh Islamic orthodoxies of countries like Saudi Arabia, including sanctions for women do not wear headscarfs, the country’s wealthiest Sultan last year ordered the introduction of Sharia law.

The announcement was met by boycotts and protests at Sultan Hassanal Bolkiah’s hotels in the U.S. and United Kingdom.

The laws, which include harsh punishments such as the slicing off of hands and feet for theft and whipping for adultery, were supposed to be implemented over three years, but their introduction has been delayed, the Sydney Morning Herald adds.