The Brotherhood of Inner Power appears to be an isolated group with no links to any Malaysian political parties or radical foreign groups. But the violence underscored one of Prime Minister Mahathir Mohamad’s greatest challenges: how to fend off the Islamic radicalism that threatens to undermine Malaysia’s multiethnic society. Many conservative Muslims detest Mahathir, who has refused to allow the application of conservative Islamic laws to all Malaysian Muslims–some 60 percent of the population. The government quickly stressed that the rebels, who tortured and killed two of the hostages before being routed, were un-Islamic. “It is not the face of Islam we want to show,” said Defense Minister Najib Razak.

Rebel leader Amin comes from Malaysia’s northern Muslim heartland. As a boy, he attended run-down religious schools where a firebrand style of Islam is taught. According to the press, Amin, 36, supports ulema–Islamic scholars–who had criticized Mahathir for his opposition to fundamentalist interpretations of Muslim law. After studying black magic in Indonesia, he returned to Malaysia, joined the Army as a private in the intelligence unit and later set up a martial-arts and religious school. He taught a volatile mix of self-defense, religion and black magic to followers ranging from engineers and accountants to former military officers. A jihad, or holy war against infidels, became the cult’s mission. The group’s Web site, which claims that the cult has some 1,000 members, shows fighters armed with Amin’s “inner power” plunging their hands in a wok of hot oil.

The cultists’ assault may bolster Mahathir’s efforts to fend off Islamic radicalism. Last month the religious police in Selangor arrested 25 Muslims, including a rock band and its female singer, for performing in a restaurant that was serving alcohol. The woman faced a three-year sentence until pro-Mahathir officials had the charges against her dropped. The government may have foiled an extremist Brotherhood. But Mahathir’s Islamic problems are far from over.