A strong earthquake has struck the Indonesian island of Sumatra, but there are no immediate reports of any casualties or damages.
The island of Nias was damaged in an earthquake in March
The quake rocked the island of Nias, where almost 1,000 people were killed in an earthquake in March.
The magnitude six quake struck at a depth of 30km (18.6 miles) off Sumatra's western coast.
The region has experienced many small tremors since the tsunami-inducing earthquake on 26 December 2004.
Sumatra is still reeling from that quake, which had a magnitude of 9.3.
The resultant tsunami is thought to have killed some 220,000 people on the island.
The US Geological Survey said the epicentre of Tuesday's earthquake was located 255km (155 miles) south-west of Medan, Sumatra.
It struck at 0852 local time (0152 GMT), Indonesia's geophysical and meteorological agency said.
The quake took place on the same fault-line as December's tremor, and struck the already fragile island of Nias, where thousands of buildings and homes were destroyed after the March earthquake.