WASHINGTON (AP) _ A severe earthquake struck the Molucca Sea off Indonesia, a spokesman for the U.S. Geological Survey here said Wednesday.

Early readings placed the epicenter of the earthquake about 140 miles east of Manado, located on the northern tip of Celebes Island, and 1,400 miles east of the Indonesia capital of Jakarta, said Don Finley, a spokesman for the USGS.

Earthquake monitors in Golden, Colo., recorded the tremor at a preliminary magnitude of 6.5 on the Richter scale. The quake occurred at 7:11 a.m. Thursday (7:11 p.m. EDT Wednesday), he said.

The Richter scale is an open-ended gauge of energy released by an earthquake as measured by ground motion recorded on a seismograph. Every increase of one number means that the ground motion is 10 times greater.

A quake with a magnitude of 4 can cause moderate damage in a populated area, a quake of magnitude 5 considerable damage, a magnitude 6 quake severe damage, one of magnitude 7 widespread, heavy damage and a magnitude 8 quake, a ''great'' earthquake capable of tremendous damage.

The tremor occurred in the same general area as an April 13, 1985 quake measuring 6.7 on the Richter scale, Finley said.

The USGS had no reports of injuries or damages, he said.