A strong, shallow earthquake rocked Indonesia's central Sulawesi province Monday evening. There were no immediate reports of serious damage or casualties, and no tsunami warning.

The U.S. Geological Survey said the quake had a magnitude of 6.8 and was centered in a thinly populated area 79 kilometers (49 miles) southeast of the provincial capital, Palu, at a depth of 9.1 kilometers (6 miles).

Imam Faturrachman, a scientist with Indonesia's Meteorology and Geophysics Agency, said the land-based quake did not have the potential to cause a tsunami.

The National Disaster Mitigation Agency posted photos of damage on Twitter from Poso, a city to the southeast of the epicenter. One showed a collapsed building and another showed a convenience store with goods strewn on its floor but otherwise intact. It said it had no reports of casualties.

El Shinta radio reported that residents ran from their homes in panic.

The first quake was followed by magnitude 5.0 and 4.9 aftershocks, also at a shallow depth.

Shallow earthquakes tend to cause more damage on the Earth's surface.

Indonesia is prone to earthquakes and volcanic eruptions due to its location along the Pacific "Ring of Fire." A powerful Indian Ocean quake and tsunami in 2004 killed a total of 230,000 people in a dozen countries, most of them in Indonesia.