Melanie Eversley

USA TODAY

Rescue workers searched for survivors Wednesday after 97 people died when a magnitude 6.5 earthquake struck off the coast of Indonesia, the U.S. Geological Survey and other sources reported.

Indonesia's national disaster mitigation agency said 78 people suffered serious injuries and dozens more were feared trapped in collapsed and damaged buildings.

The death toll was expected to rise, Indonesia's army said.

TV footage showed rescuers in orange uniforms shining flashlights into the interiors of broken buildings as they searched for signs of life, the Associated Press reported.

However as night fell in the area rescue efforts were hampered.

The shallow earthquake struck at 5:03 a.m. local time (5 p.m. ET Tuesday) and was centered about 6 miles north of Reuleut, a town in northern Aceh. It had a depth of 11 miles. It did not generate a tsunami.

"The earthquake was felt strongly and many people panicked and rushed outdoors as houses collapsed," Sutopo Nugroho of Indonesia's National Disaster Management Agency, said in a statement.

The quake was another terrifying reminder of their region’s vulnerability to natural disasters. More than 100,000 died in Aceh after the Dec. 26, 2004, earthquake triggered a devastating tsunami.

“It was very bad, the tremors felt even stronger than 2004 earthquake,” Musman Aziz, a resident of the area, told the AP. “I was so scared the tsunami was coming.”

More than 40 buildings including several mosques were flattened in the district located 11 miles southwest of the of the epicenter.

At least five aftershocks were felt following the initial quake, according to the disaster mitigation agency.

Indonesia is prone to earthquakes due to its location on the Pacific “Ring of Fire,” an arc of volcanoes and fault lines in the Pacific Basin, the AP said. The 2004 quake and tsunami killed a total of 230,000 people in a dozen countries.

More than half of Indonesia's population of 148 million live in quake-prone areas.