A moderate earthquake shook southwestern Guatemala on Sunday, alarming residents but causing no injuries or damage, the national disaster prevention agency said, according to AP. The quake had a preliminary magnitude of 5.1 and was centered just offshore in the Pacific Ocean about 48 kilometers (30 miles) south of the city of Mazatenango, according to the U.S. Geological Survey. It struck just before 11 a.m. local time. A magnitude-5.6 quake rattled the Central American nation Friday night, knocking out power and blocking roads, and there have been several minor tremors since.