JAKARTA, Indonesia - A strong earthquake struck deep under the sea in eastern Indonesia on Saturday, but there were no immediate reports of damage or injuries, officials said.

The earthquake of a preliminary magnitude of 6.0 struck on the fifth anniversary of another quake that spawned the Asian tsunami that left 230,000 people dead in a dozen countries around the Indian Ocean rim. The Dec. 26, 2004 tsunami was sparked by a 9.2-magnitude underwater quake off the Indonesian island of Sumatra.

Saturday's quake was at a depth of 35 miles (57 kilometres), too far below the earth's surface to cause a tsunami, said Indonesian Meteorology and Geophysics Agency seismologist Paulus Prihandoyo.

The quake had its epicenter about 165 miles (270 kilometres) north of Saumlaki and about 1,680 miles (2,700 kilometres) east of the capital Jakarta, the U.S. Geological Survey said.

Residents in Saumlaki said the quake panicked people and caused an electricity blackout, but there were no reports of damage or injuries.

Indonesia sits above a series of fault lines that make the vast island nation one of the most earthquake-prone places in the world.

A magnitude 7.6 earthquake struck off West Sumatra on Sept. 30 and killed hundreds of people and toppled hundreds of homes and buildings.