An earthquake measuring 6.7 on the Richter scale rocked Indonesia's Sumatra island early Tuesday, killing at least two people, officials said. The quake struck at 12:55 am (1755 GMT Monday) with an epicentre 59 kilometres north-east of Singkil Baru district in Aceh province, at a depth of 78 kilometres, according to the Meteorology, Geophysics and Climatology Agency. Two people, including an 11-year-old boy, were killed by falling debris while a nursing school and three houses were badly damaged, said Sutopo Nugroho, a spokesman for the National Disaster Management Agency. Residents in Aceh's Meulaboh district fled to higher ground, fearing a tsunami, according to a report of the German Press Agency "DPA".