Clip from Indonesia Earthquake Sumatra 8.7 HD

Indonesia issues tsunami warning after a 8.7 magnitude earthquake hit waters off westernmost Aceh province.

An earthquake with an initial magnitude of 8.9 has struck under the sea off Indonesia's northern Aceh province.

The quake triggered a tsunami warning across the Indian Ocean region.

The Pacific Tsunami Warning Center said it was not yet known whether a tsunami had been generated, but advised authorities to 'take appropriate action'.

The region is regularly hit by earthquakes. The Indian Ocean tsunami of 2004 killed 170,000 people in Aceh.

The US Geological Survey, which documents quakes worldwide, said the Aceh quake was centred 33km (20 miles) under the sea about 495km from Banda Aceh, the provincial capital.

It was initially reported as 8.9 magnitude but was later revised down to 8.7 by the USGS.

The tsunami centre's warning said quakes of such a magnitude 'have the potential to generate a widespread destructive tsunami that can affect coastlines across the entire Indian Ocean basin'.

The tremor was felt as far away as Singapore, Thailand and India.

Reuters reports that people in the region were making their way to higher ground.

The BBC's Karishma Vaswani in the Indonesian capital Jakarta says there were reports of the ground.