7.5-Magnitude Quake Hits off Indonesia

map of Indonesia with quake locator in western Sumatra
A strong earthquake hit late Monday off the western coast of Indonesia's Sumatra island, but no damage or casualties were immediately reported.

The 7.5-magnitude temblor struck at a depth of 9 miles on a small island off Sumatra, the U.S. Geological Survey said. A massive earthquake and tsunami struck off the same island in 2004.

It was reportedly felt in five towns in Bengkulu and West Sumatra provinces, but so far there no reports of damages or casualties, said Tatok Yatimantoro of Indonesia's Meteorology and Geophysics Agency.

The tremor that struck at 9:42 p.m. (1642 GMT) was centered about 48 miles southwest of the Pagai Selatan in Mentawai Island, with a depth of 6 miles, according to the Indonesian agency.

A tsunami watch for local areas was issued but lifted within an hour.

The world's largest archipelago, Indonesia is prone to earthquakes and volcanic activity due to its location on the so-called Pacific Ring of Fire.

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Meanwhile, Indonesia warned Monday that its most volatile volcano could erupt at any time and started evacuating some of the thousands of villagers living on the mountain's slope.

Mount Merapi has seen increased volcanic activity over the past week and officials have raised the alert level for the 9,737-foot-high mountain to the most urgent level, said government volcanologist Surono, who uses only one name.