A strong earthquake with a preliminary magnitude of 5.1 struck the western Greek island of Kefalonia on Monday, the Athens Geodynamic Institute said. There were no immediate reports of damage or injuries.

The quake struck at 9:29 a.m. (2:39 a.m. EDT) and had an epicenter beneath the seabed off the west coast of the island, 185 miles west of Athens, the institute said.

The island was the scene of at least one forest fire, which broke out overnight in southern Kefalonia. Vast areas of the country have been burned by massive wildfires that have been raging out of the control since Friday.