Strong earthquake rocks eastern Indonesia

A strong undersea earthquake shook eastern Indonesia on Tuesday, but there were no immediate reports of serious damage or casualties.

The U.S. Geological Survey said the 6.3-magnitude quake struck about 110 kilometers (68 miles) off Tobelo, a coastal town on Halmahera Island in North Maluku province. It said the quake was centered about 63 kilometers (39 miles) beneath the sea.

The Indonesian Meteorology and Geophysics Agency said the quake was unlikely to trigger a tsunami.

Indonesia, the world's largest archipelago nation with 240 million people, is prone to seismic upheaval due to its location on the Pacific "Ring of Fire," an arc of volcanoes and fault lines encircling the Pacific Basin.

A massive quake off the coast of Aceh in 2004 triggered a powerful tsunami that killed around 230,000 people in a dozen countries.