At least 113 people were dead and over 150 missing a day after a powerful earthquake struck off Indonesia's Mentawai islands, triggering a tsunami with waves up to three metres high, officials said on Tuesday.
The Disaster Management Agency in West Sumatra province said 10 villages on the island chain were hit by a tsunami caused by Monday's 7.2 magnitude quake.
Mujiarto, head of the health ministry's crisis centre, said the latest information from Mentawai showed "113 people were dead and at least 150 others were missing".
The National Disaster Management Agency said most of the deaths occurred in Pagai Utara and Pagai Selatan districts. It reported 645 displaced families and many homes destroyed by the waves.
Authorities had lifted a tsunami warning one hour after the quake and initially said there were no reports of casualties or damage.
"The information came late because communication was difficult," said agency chief Harmensyah, who like many Indonesians uses only one name.
Local legislator Hendri Dori Satoko told Metro TV that he received a report saying 40 people were killed and more than 300 people were missing after the quake.
The health ministry said dozens of homes were swept away or destroyed by a tsunami minutes after the quake, where waves reached as far as 600 metres inland and submerged dozens of houses.
On Pagai Utara island, up to 80 per cent of homes in Betumonga village were destroyed, leaving "many people" missing and feared dead, Mujiarto said.
Andi Arief, a presidential aide in charge of disaster relief, said relief workers were en route to the Mentawais to provide emergency assistance. A boat trip to the islands takes about 10 hours from the provincial capital Padang on Sumatra.
The Mentawai chain consists of 70 islands and islets with a population of about 68,000 people, 150 km off the western coast of Sumatra.
Experts have warned that a massive undersea earthquake is likely to occur in the future beneath the Mentawais and could trigger a deadly tsunami similar to the one that devastated Indian Ocean nations in December 2004.
That tsunami killed more than 230,000 people, including about 170,000 in Indonesia's Aceh province on Sumatra.
Monday's quake was also felt strongly in several areas of western Sumatra, panicking residents in Padang.
A 7.6 magnitude earthquake hit Padang and neighbouring districts on Java in September 2009, killing more than 1,000 people.
Indonesia sits on the so-called Pacific Ring of Fire, where continental plates meet, causing earthquakes and volcanic eruptions.
Authorities also began evacuating villagers from the slopes of Mount Merapi volcano on central Java island after scientists upgraded its alert status to the highest level on Monday.