The U. S. Geological Survey has reported that a magnitude 7.7 earthquake struck northern Sumatra, Indonesia on Wednesday.

The USGS has said that the quake struck about 5:15 a. m. local time. It was centered about 525 miles west of Kuala Lumpur and about 125 miles west-northwest of Sibolga, Sumatra.

Authorities assessed the quake to be of magnitude 7.8, but the figure was subsequently revised.

No immediate information was available about injuries or property damage.

A local tsunami watch has been issued by the National Oceanic and Atmospheric Administration Pacific Tsunami Warning Center.

The center said in a statement, "Sea level readings indicate a tsunami was generated. It may have been destructive along the coasts near the earthquake epicenter."

Local authorities "can assume the threat has passed" if damaging waves do not occur within 2 hours, after the watch was issued in those areas, the center further added.

The statement also said, "No tsunami threat exists for other coastal area in the Indian Ocean although some other area may experience small sea level changes and strong or unusual coastal currents." (With inputs from Agencies)