JAKARTA, Sept. 28 (Xinhua) -- A shallow under-earth quake of revised magnitude 7.7 on the Richer scale rattled the Sulawesi province of central Indonesia on Friday.

The quake was potential for tsunami, official of meteorology and geophysics agency Suci Dewi told Xinhua by phone.

The warning was lifted within the hour, but officials asked people in affected area to remain on the alert as a number of moderate aftershocks hit the area.

"We advise people to remain in safe area, stay away from damaged buildings," Sutopo Purwo Nugroho, spokesman for the National Disaster Mitigation Agency, said in a televised interview.

He added that the national agency in Jakarta was having difficulties reaching some authorities in the area.

The U.S. Geological Survey put the magnitude of the second quake at a strong 7.5, after first saying it was 7.7.

The earlier quake destroyed some houses, killing one person and injuring at least 10, authorities said.

"The (second) quake was felt very strongly, we expects more damage and more victims," Nugroho said.

A series of earthquakes in July and August killed nearly 500 people on the holiday island of Lombok, hundreds of kilometres southwest of Sulawesi.