(CNN) -- A strong earthquake struck the Mariana Islands region in the Pacific Wednesday, the United States Geological Survey's National Earthquake Information Center reported.
The quake was a magnitude 6.1, the Center said, and was centered about 240 miles west-southwest of the U.S. territory of Guam. It hit about 12:28 p.m. EDT.
The Mariana Islands region was hit overnight Sunday by a moderate quake - 5.0 - and overnight Saturday by a strong tremor - 6.3 - the Center said.
As yet, the Pacific Tsunami Warning Center has not issued an alert.