Suspected Islamic separatist militants shot and killed five people in two days in Thailand's troubled south, police said Wednesday. A 57-year-old defence volunteer was shot dead in Yala province on Tuesday night as he arrived home from daily prayers at the local mosque, they said. Overnight Tuesday, a 41-year-old woman was shot dead in Narathiwat province while her son was on duty as a defence volunteer. Defence volunteers are villagers trained and armed by security forces to fight the Islamic insurgency, which has killed more than 3,700 people in the past five years. Two other defence volunteers, aged 37 and 26, were shot and killed on Wednesday morning, also in Narathiwat, while a Buddhist man, 52, was shot dead on his way home from a market in Pattani province later that day.