The Indonesian government issued a tsunami warning on Friday after another earthquake struck off the western coast of Sumatra Island, an official said, according to DPA. The tremor, measuring as high as 6.9 on the Richter scale, struck at 1:01 p.m. (0601 GMT) and was 153 kilometres south-west of Bengkulu province. The epicentre was at a depth of 10 kilometres, according to the US Geological Survey, which measured the quake at 6.4 on the Richter Scale. However, Indonesia's Meteorology and Geophysics agency reported the magnitude at 6.9.