An earthquake measuring 6.4 on the Richter scale struck western Indonesia on Thursday morning, but there is no report of damage or casualty so far, local meteorology agency said.

The epicenter of the quake, which occurred at 3:01 a.m. local time (2001 GMT Wednesday), is located at a depth of 50 km below the sea level, 32 km south-west of Mentawai Islands and off the western coast of Sumatra, the Geophysical, Climatological and Meteorological office (BMG) said in a statement.

But the office did not say whether the earthquake has potential to trigger a tsunami.

Indonesia sits on a vulnerable quake zone so called the PacificRing of Fire, where two continental plates meet and cause frequent seismic and volcanic activities.

(Xinhua News Agency April 16, 2009)