A Malaysian laundrette that banned non-Muslim customers sparked anger Tuesday as fears grow of creeping religious conservatism in the multi-ethnic country.

The self-service shop in the town of Muar, in the southern state of Johor, put up a sign saying that it would only allow Muslim customers.

Malay Muslims make up the majority of Malaysia's approximately 30 million inhabitants but the country is also home to sizeable ethnic Chinese and Indian minorities, and restricting shops or services to a certain religion is rare.

A member of Johor state's royal family, prince Tunku Idris Sultan Ibrahim, led condemnation of the laundrette, saying in an Instagram post: "Is this for real? This is too extreme. I'm appalled."

An Islamic cleric in the northern state of Perlis, Mufti Mohd Asri Zainal Abidin, warned that the restriction was an example of "narrow-mindedness", the Star newspaper reported.

But the shop's owner defended the move, saying that "95 percent" of his customers were Muslim. 

"There are other laundrettes available nearby. So, it wouldn't be a problem for non-Muslims if they needed to find another place to wash their clothes," he was quoted as saying by news website Free Malaysia Today.

Critics say that Malaysia's traditionally tolerant brand of Islam is being eroded by increasingly influential Muslim hardliners.

Last week, authorities in Kuala Lumpur cancelled an annual beer festival after an Islamist party warned it would turn the capital into "the biggest centre of vice in Asia".