ATHENS, Greece— A strong earthquake with preliminary magnitude of 5.1 shook parts of central Greece early Friday, damaging more than a dozen buildings but causing no injury, seismologists and local authorities said.

The Athens Geodynamic Institute said the quake struck at 2:46 a.m. Friday (0046GMT) near the town of Nafpaktos, some 100 miles (160 kilometers) northwest of Athens. It was followed by four aftershocks ranging between magnitudes of 4.4 and 4.7.

Local authorities said several schools were closed in the area as a precaution after the quake damaged older and mostly uninhabited buildings in Nafpaktos and surrounding villages.

A 5.2-magnitude tremor occurred in the same region on Tuesday.

Greece is one of the most earthquake-prone countries in the world, but the thousands of quakes recorded each year rarely cause severe damage or injuries.

In 1999, a magnitude 5.9 earthquake killed 143 people in Athens. (AP)