Powerful earthquakes jolted the Indonesian island of Sulawesi on Friday, damaging houses and killing at least one person.

The U.S. Geological Survey said the strongest of two major quakes had a magnitude of 7.5 and was centered at a depth of 6 miles (10 kilometers) about 35 miles (56 kilometers) northeast of the central Sulawesi town of Donggala. The quake briefly triggered a tsunami warning.

An official with the local disaster agency, Akris, said "many houses have collapsed."

"It happened while we still have difficulties in collecting data from nine villages affected by the first quake," he told The Associated Press. "People ran out in panic."

National Disaster Mitigation Agency spokesman Sutopo Purwo Nugroho said communications with the region are disrupted.

"Our early estimation, based on experience, is that it caused widespread damage, beginning from (the provincial capital) Palu northward to Donggala," he told MetroTV in an interview.

The area was hit earlier Friday by a magnitude 6.1 earthquake that based on preliminary information killed one person, injured 10 and damaged dozens of houses.

Indonesia is prone to earthquakes because of its location on the "Ring of Fire," an arc of volcanoes and fault lines in the Pacific Basin.

In December 2004, a massive magnitude 9.1 earthquake off Sumatra in western Indonesia triggered a tsunami that killed 230,000 people in a dozen countries.