Updated

A strong earthquake has struck waters of western Indonesia, prompting local officials to issue a tsunami warning.

The U.S. Geological Survey said the quake had a preliminary magnitude of 7.3 and struck 260 miles off the coast of Aceh province. The USGS Pacific Tsunami Warning Center said a destructive, widespread tsunami is not expected, although there is a "very small possibility" of a local tsunami.

The earthquake was centered 18.1 miles beneath the ocean floor.

Arief Akhir, an official with Indonesia's geological agency, said a tsunami warning has been issued. But more than an hour after the quake, there were no signs of seismically triggered waves.

Indonesia is prone to seismic upheaval due to its location on the Pacific "Ring of Fire," an arc of volcanos and fault lines encircling the Pacific Basin. A giant quake off the country on Dec. 26, 2004, triggered a tsunami in the Indian Ocean that killed 230,000 people, half of them in Aceh.

The Associated Press contributed to this report.