JAKARTA, Indonesia - A 7.3-magnitude earthquake struck Sunday in the Molucca Sea about 100 miles east of Sulawesi Island in northeastern Indonesia, the U.S. Geological Survey said.

The quake was large enough to cause a tsunami, the Pacific Tsunami Warning Center said in a statement, but no tsunami warning was immediately issued.

The epicenter of the major quake was about 80 miles from the city of Ternate, in north eastern Indonesia, it said. It had a depth of more than six miles below the ocean floor.

An official with the Pacific Tsunami Warning Center in Hawaii told The Associated Press that a basin-wide tsunami - one that travels a great distance or across an ocean - isn't expected, though a tsunami near the earthquake's site is ''always possible.''

''Given the size of the earthquake, we think a basin-wide tsunami isn't likely, though a local tsunami could be possible,'' said Brian Shiro, a geophysicist at the tsunami center.

Indonesia, the world's largest archipelago, is prone to seismic upheaval due to its location on the so-called Pacific ''Ring of Fire,'' an arc of volcanos and fault lines encircling the Pacific Basin.

In December 2004, a massive earthquake struck off Indonesia's Sumatra island and triggered a tsunami that killed more than 230,000 lives - 131,000 people in Indonesia's Aceh province alone.