Hospitals, schools and two government buildings suffered some damage, disaster-management officials say [Reuters]

A powerful earthquake has hit waters off Indonesia's resort island of Bali, sending people fleeing homes and hotels in panic.

No tsunami alert was issued but Thursday's quake left at least 50 people injured.

Indonesia's geological agency put the quake's magnitude at 6.8, but the US Geological Survey said it was 6.0.

The reason for the discrepancy was not immediately clear.

Most of the injured suffered cuts, broken bones and head wounds, Wayan Sudanti, a hospital spokesman, said.

They included 12 students and three teachers injured when the ceiling of their high school caved in, according to I Gede Tejo of the local disaster agency.

The quake rocked the main tourist district of Kuta for several minutes, Endro Tjahjono, from the Bali office of Indonesia's Meteorology and Geophysics Agency, said.

"There was panic - everyone ran out of the buildings. When we returned to our office building, we saw some cracks on the wall and plaster had come off the walls," he told the AFP news agency.

Several hospitals, three schools and two government buildings suffered some damage, Sutopo Purwo Nugroho, a spokesman of the Indonesian National Disaster Management Agency, told AFP.

Hundreds of terrified tourists on Kuta's beach strip raced from their hotels, officials and hotel staff said.

"It was a chaotic scene. Tourists dashed out of their hotels to the roads screaming 'Quake! Quake!'," Perry Markus, Bali Hotels and Restaurant Association secretary-general, said.

The quake struck 60km beneath the ocean floor.

Source: Agencies