Jakarta, Indonesia (CNN) -- The death toll in Tuesday's earthquake in Indonesia has risen to 35, authorities said. The number of those injured stands at 275.
Most of the victims were children and the elderly, who were struck by falling debris, said disaster management spokesman Sutopo Purwo Nugroho. Rescuers are searching for a dozen people who were reported missing.
Thousands of homes, schools and mosques sustained damages, when the 6.1-magnitude quake struck in the country's northwest. The quake also triggered landslides that cut off roads, Nugroho said.
The death and destruction was concentrated in the province of Aceh on the island of Sumatra. The two hardest-hit districts were Bener Meriah and Central Aceh, the country's National Disaster Management Agency said.
People ran out of their homes when the quake struck, and many residents were hesitant to return for fear of aftershocks, Nugroho said.
In 2004, a 9.1-magnitude underwater earthquake off the coast of Sumatra triggered a tsunami that killed more than 200,000 people in 14 countries. The majority of the deaths were in Indonesia, with Aceh bearing the brunt.
Tuesday's quake struck at a depth of 10 kilometers (about 6.2 miles) in a mountainous area near Sumatra's northwestern tip, the U.S. Geological Survey said. It was followed by at least two aftershocks of magnitude 5.2 and 5.3.
Indonesia is on the Ring of Fire, an arc of fault lines circling the Pacific Basin that is prone to frequent earthquakes and volcanic eruptions.
CNN's Kathy Quiano reported from Jakarta amd Ben Brumfield wrote from Atlanta