A magnitude 7.2 earthquake and three dozen aftershocks injured at least 42 people and set off a tsunami warning in eastern Indonesia.

The strongest quake struck 195 miles (320 kilometers) north of the Sulawesi island coast at 1:34 A.M. today in Indonesia (12:34 P.M. Eastern time yesterday), according to the U.S. Geological Survey (USGS). The strongest aftershock measured 6.2 on the Richter scale.

The tsunami warning lasted only an hour, according to the Associated Press. But that was long enough to scare residents, they told the newswire. "We were so afraid," said Damian Geruh, adding that women were screaming as they fled their homes. "We ran to nearby hill. I saw others climbing trees."

Indonesia is part of the "Ring of Fire," an area of active volcanoes and fault lines around the Pacific Basin. The country’s Aceh province was the hardest hit in the devastating December 2004 tsunami, which killed an estimated 230,000 people following a massive, magnitude 9.2 earthquake.

Learn more in our In-Depth Report guide to earthquakes.

Map of Indonesia/CIA World Factbook via Wikimedia