SINABANG, Indonesia (Reuters) - A major earthquake of 7.7 magnitude struck off the coast of Aceh on the Indonesian island of Sumatra on Wednesday, but there were no immediate reports of casualties.
A Reuters photographer in Sinabang on Simeulue island, south of Aceh, said there was panic and electricity was cut off after the quake. Metro TV reported that people rushed to higher ground in some areas.
Aceh Governor Irwandi Yusuf said there had not been reports of damage or casualties so far.
"I am on the coast now, some people had gone to take refuge on higher ground but now they have returned to their homes," Yusuf told Metro TV.
The quake, which struck around 5:15 a.m. (2215 GMT), was centred 200 km (125 miles) west-northwest of the coastal town of Sibolga and was at a depth of 31 km, the U.S. Geological Survey said. The epicentre was around 215 km from Medan, the largest city on Sumatra.
The Reuters witness said there were at least three aftershocks.
The Hawaii-based Pacific Tsunami Warning Center initially warned the quake could generate a local tsunami, but later cancelled its tsunami watch, saying: "Sea level readings indicate that a significant tsunami was not generated."
An official from Indonesia's meteorology agency said a tiny tsunami of only 3 cm (1 inch) had been detected at Sinabang and lifted its own tsunami warning.
A Metro TV reporter in the Sibolga area of North Sumatra said that he fell off his motorbike when the quake struck and the force left electricity poles swaying for minutes afterwards.
In December 2004, a magnitude 9.15 quake off the coast of Sumatra's Aceh province triggered an Indian Ocean tsunami that killed about 226,000 people in Indonesia, Sri Lanka, India, Thailand and nine other countries.
(Reporting by Ed Davies, Telly Nathalia and Olivia Rondonuw; Editing by Alex Richardson)