A powerful earthquake measuring 6.1 magnitude on the Richter scale struck southeast of the Pacific island nation of Tonga on Sunday, the US Geological Survey said. 
The quake hit 277 kms (172.12 miles) south-southeast of the capital Nuku'alofa at a depth of 66 kms, the USGS said. 
Earlier USGS tweeted the preliminary reading of the quake to be 5.8. 
The part of the South Pacific Ocean where Tonga lies is considered to be one of the most seismically active areas in the world due to convergence between the Australia and Pacific plates, the USGS said.

Source: QNA