An undersea earthquake measuring 6. 0 on the Richter scale struck off Sumatra island earlier Thursday, but no tsunami threat and damage or casualty were reported, officials said.

The quake jolted at 07:16 a.m. Jakarta time (0016 GMT) with the epicenter at 37 km southwest Mukomuko of Bengkulu province of Sumatra and with a depth at 28 km under sea bed, an official of the Meteorology and Geophysics Agency told Xinhua by phone.

The intensity of the quake was felt by 4 to 4 MMI (Modified Mercally Intensity) in Mukomuko, 3 MMI in Bengkulu city, the capital of Bengkulu province and Padang Pariaman of West Sumatra province and Jambi province, he said.

The USGS reported on its website that the quake was measured at 5.8 magnitude.

Disaster Management and Mitigation Agency officials in Bengkulu and West Sumatra told Xinhua by phone that there were no building damaged or people injured after the quake, including in the hardest hit area of Mukomuko.

"No reports of damage or fatality we have got so far," Aidil, an official of the agency in Bengkulu, said.

Nevertheless, a local television reported that the quake had triggered panic among patients in a hospital, they rushed out of the rooms and prefer to stay outside for fear of a repeat of strong quake years ago that killed over one thousand people in the area.

"But, as a whole there were no damage or people injured," said Muchtar Moesa, an official at the disaster management and mitigation agency in West Sumatra.

Indonesia is prone to earthquakes as it lies on a vulnerable quake-hit zone so called "the Pacific Ring of Fire."