Seismologists say an earthquake with a preliminary magnitude of 5.1 has struck the northern Greek region of Halkidiki, rattling the area but causing no damage or injuries.
The Athens Geodynamic Institute said the quake struck Friday morning, 89 kilometers (55 miles) south of the country's second-largest city of Thessaloniki, and 271 kilometers (135 miles) north of Athens.
Greece is in a highly seismically active part of the world, but the vast majority of earthquakes do not cause severe damage or casualties, AP reported.
In January and February, two quakes with magnitudes of about 6 struck the western Greek island of Kefalonia, damaging buildings and leaving many homeless for weeks, but causing no serious injuries.
According to Reuters, a moderate earthquake was felt in El Salvador on Thursday night, but there were no immediate reports of injuries or damage.
The U.S. Geological Survey said a 4.9 quake struck offshore about 40 miles (65 km) south of the coastal town of Chirilagua at a depth of 44 miles (70 km).