Thousands of Indonesians prayed for their loved ones at mass graves and mosques today to mark a tsunami which devastated Aceh province 12 years ago. It was one of the worst natural disasters in human history.<br/><br/>Some 170,000 lives were lost in the country when a 9.1- magnitude quake struck Aceh, a predominantly Muslim province in the northern tip of Sumatra island. The quake brought about massive waves that also hit coastal areas as far away as Somalia.<br/><br/>Graves across the province, including in Siron in Aceh Besar district where more than 46,000 were buried, were crowded with people who scattered flowers on the earth where they believe the remains of their loved ones lie to rest. Indonesia sits on the Pacific "Ring of Fire", where the meeting of continental plates causes strong seismic activity, and is frequently hit by earthquakes.<br/>