A powerful earthquake rocked the Indonesian island of Sulawesi Friday, triggering a 10-foot-tall tsunami that an official said swept away houses in at least two cities. It was the latest in a series of quakes that killed nearly 500 people in the country last month.

The U.S. Geological Survey said the magnitude 7.5 quake was centered at a depth of 6 miles, about 35 miles northeast of the town of Donggala. Earlier Friday, the same area was hit by a magnitude 6.1 earthquake that killed one person, injured 10 and damaged dozens of houses.

An official with the Akris local disaster agency said that "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."

Disaster agency spokesman Sutopo Purwo Nugroho said the tsunami hit Palu, the capital of central Sulawesi province, as well as the smaller city of Donggala and several other coastal settlements.

Indonesian TV showed a smartphone video of a powerful wave hitting Palu, with people screaming and running in fear. The water smashed into buildings and a large mosque that collapsed under the force.

Houses were swept away and families were reported missing, Nugroho said, adding that communications and power to the area were disrupted.

He said communications with the region had been 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.

Indonesia, a sprawling archipelago that straddles the Pacific "Ring of Fire," is prone to earthquakes and volcanic eruptions.

The island of Lombok was rocked by a series of tremors in August that triggered landslides and kiled at least 460 people.

In 2004, a big earthquake off the northern Indonesian island of Sumatra triggered a tsunami across the Indian Ocean, killing 226,000 people in 13 countries.