Indonesia on Friday promised a full investigation into the public humiliation, mob beating and possible caning under Islamic law of two people suspect

The offences allegedly took place Wednesday after a 36-year-old teacher and a 28-year-old housewife were accused of having extramarital sex in Aceh province, where religious police enforce Shariah or Islamic regulations.

They were dragged from the woman’s home by an angry mob, paraded naked through their village, tied to a post and beaten almost to death, and now face nine lashes each in public, police said.

It is the latest incident to expose the conflict between local Shariah provisions and rights enshrined in the secular constitution of the world’s most populous Muslim-majority country.

“This is a barbarous crime and obviously against our rule of law,” an official at the justice and human rights ministry said.

“We will order police to launch an immediate probe and to take firm and concrete action against the perpetrators.”

Nearly 90 percent of Indonesia’s 234 million people are Muslims, but the vast majority practise a moderate form of the religion.

National human rights commission chairman Ifdhal Kasim urged President Susilo Bambang Yudhoyono to clarify that rights guaranteed under the constitution take supremacy over local regulations, including religious ones.

“This can be a bad precedent for other regions which have similar tendencies and which try to put religious values above the country’s constitution,” he told AFP.

“The directive should mention that Indonesia is a secular country and everything should be based on the constitution.”

Deeply Islamic Aceh adopted partial Shariah law in 2001 as part of an autonomy package aimed at quelling separatist sentiment.’

Last year the outgoing provincial government passed the Qanun Jinayat, a bill allowing adulterers and other religious offenders to be put to death by stoning.

It has not been signed into law by Governor Irwandi Yusuf and officials in Jakarta have asked for it to be withdrawn.