A powerful undersea earthquake struck near Fiji on Tuesday, and officials issued a tsunami alert for the local area.

The 6.3 magnitude quake occurred at 3:16 p.m. local time about 150 miles northeast of Vanua Levu, the main tourist spot in Fiji's chain of islands. The U.S. Geological Survey said it was 18 miles deep.

No damage or injuries were immediately reported.

The agency initially reported a second quake nearby, much deeper and with a magnitude of 6.8. But the USGS removed the second quake from its Web site soon after the details were posted, saying it was glitch.

The USGS says it is common for seismological equipment in the area to incorrectly record multiple temblors when a large earthquake occurs.

The Hawaii-based Pacific Tsunami Warning Center said there was no Pacific-wide threat of a destructive tsunami but that quakes of the size measured Tuesday could cause damaging local tsunamis.

Nilesh Kumar, technical officer at Fiji's Mineral Resources Department, said there had been no reports in Fiji of either the ground shaking or large waves on the horizon.