The 'Kaum Zahid' of Cambodia practises an esoteric version of Islam. They believe in Alah and His Messenger, Muhammad. However they pray only once a week and fast only for three days in Ramadan. They are only obliged to practise Islam at the age of 40 (the age when Muhammad became a prophet). They constitute about 5% of the half million Muslims in Cambodia. (The 95% majority of Muslims in Cambodia are Sunnis. They practise the Shafie school of thought in Islam). The Kaum Zahid claims that they are the original Cham Malays who came from Vietnam to Cambodia. The community is concentrated at Kampong Chnang.