The meteorological office has issued a 'very strong' wind warning valid until 11pm on Thursday, with the possibility that a cyclone hitting Greek island also affecting our shores.

The weather forecasters are indicating a North Northeast wind force 6 locally force 7, decreasing to force 5 to 6 locally force 6 to 7. The sea is also rough, locally rough to very rough.

Greece's civil protection services went on alert Thursday as the country braced for the threat of a cyclone, forest fires prompted evacuations on an island and an earthquake rattled the south of the country.

Gale-force winds of up to 100 kilometers per hour (62 mph) slammed into Greece from the west, and meteorologists warned about the possibility of a cyclone in the Ionian Sea.

The high winds forced ferries to remain in port Thursday, severing Greek islands' connection to the mainland. The strong winds toppled trees onto power lines in the northern suburbs of Athens, with the fire department saying it received more than 500 calls to remove debris.

Authorities in the Saronic municipality near Athens, on the Ionian island of Zakynthos and the Aegean islands of Tinos, Andros and Mykonos ordered schools to remain shut. Schools in greater Athens will also be closed Friday.

On the western island of Kefallonia, several villages were evacuated as wildfire was being fanned by the strong winds. The island's emergency services were on alert as weather conditions were expected to worsen.

Meteorologists warned of the high probability that a Mediterranean cyclone known as a medicane — which combines the words Mediterranean and hurricane — could form Friday in the Ionian Sea southwest of the Greek mainland.

Severe weather warnings were issued through Sunday, with the storm expected to gradually move eastward.