A strong 6.1-magnitude earthquake struck off the Indonesian coast early today. No tsunami warning was issued and there were no immediate reports of damage.<br />''  <br />''According to the United States Geological Survey the quake hit at a depth of 31 kilometres off Sumba island. It was followed by a weaker quake in the same area with an initial reading of 5.2 magnitude, according to Indonesia's disaster agency.<br />''<span style="color: #222222;"> </span><br />