A tsunami triggered by a 7.7-magnitude earthquake left hundreds of people missing or dead and thousands homeless Tuesday in Indonesia, authorities said.
The quake struck Monday off the coast of Sumatra. Henry Dori Satoko of the Mentawai Islands parliament told CNN many of those unaccounted for were attempting to flee to higher ground. CNN said large waves were keeping rescue workers from the area.
Officials reported at least 112 dead and 502 missing. Other estimates put the death toll as high as 180.
A spokesman for the Indonesian Health Ministry said victims reported seeing waves 10 feet high in an area that is a magnet for surfers.
The officials told Xinhua, China's official news agency, that emergency relief efforts began immediately after the quake struck Monday evening.
The National Disaster Management Agency said Tuesday pressure building up beneath a lava dome resulted in a series of four explosions, The New York Times reported.
Spokesman Priyadi Kardono said agency workers were "in the process of evacuating everyone down to the shelter areas."
"The problem is that a lot of people have left it late, so a number have been burned," Kardomo said.
The chief of West Sumatra's disaster agency said six villages on Mentawai Island west of Sumatra were affected by the tsunami, Indonesia's Antara news agency reported.
Waves leveled the village of Silabu, a Health Ministry crisis center spokesman, told Xinhua.
More than 600 families evacuated to higher ground.
A spokesman for Indonesia's Meteorology, Climatology and Geophysics Agency said at least 95 aftershocks had occurred since the quake struck. The strongest measured 5 on the Richter scale.
Two tectonic plates meet at the city of Padang and the Mentawai Islands. A Dec. 26, 2004, 9.1-magnitude quake and tsunami killed more than 225,000 people in Indonesia and 13 other countries.