KUALA LUMPUR, Malaysia -- Like a vast majority of Muslims in Malaysia, Mohammad Shah was raised according to the Sunni school of Islam. But when he was about 30, he said, he came to believe that Sunni teachings did not answer all of his questions about Islam. He began reading about the Shiite school of thought, the world’s second-largest Islamic branch, and decided that “Sunni was not right for me.”

“I consider myself the new generation of Malaysian Shia,” said Mr. Mohammad, 33. “My father is Sunni, my mother is Sunni. They are aware that I’m practicing a different school of thought. It’s no problem at all.”