Indonesia ? A powerful earthquake rattled northeastern Indonesia today, briefly triggering a tsunami alert and sending panicked residents fleeing from homes and buildings, officials said.

The quake had a preliminary magnitude of 6.6 and struck 55 miles beneath the Molucca Sea, the U.S. Geological Survey.

Indonesia’s seismological agency put the magnitude at 7.6 and immediately issued a tsunami alert over the radio and television. It was revoked one hour later after the threat had passed.

In Japan, a magnitude 7 quake hit off the coast of the northern island of Hokkaido early today, triggering a small tsunami that apparently caused no injuries or damage, Japan’s Meteorological Agency said.