An earthquake measuring 5.9 on the Richter scale rattled the Greek island of Zankynthos in the Ionian Sea on Tuesday, the Athens Observatory's Geodynamic Institute said.
No serious damage was reported from the quake, which was recorded at 8:29 pm (1729 GMT) and was centered off Greece's Peloponnesian coast, although the event caused panicked residents to flee their homes and gather in the streets, the institute reported.
Another earthquake measuring 5.7 on the Richter scale also struck in the same area, off Zankynthos, overnight Monday.
The Greek island of Carpathos in the southeastern Aegean Sea was also shaken early Monday by an earthquake measuring 5.2 points on the open-ended Richter scale.
The Zankynthos tremors were described as "strong" by the institute but director George Stavrakakis said he felt it was "very difficult for the same epicenter to produce an even stronger earthquake".
He said the institute's seismologists were "following the phenomenon carefully" and urged residents to stay calm.
Schools in Zankynthos, one of the most seismically active areas in quake-prone Greece, were closed Tuesday as a safety precaution and civil engineers conducted checks on public buildings.
Half of all earthquakes recorded in Europe are in Greece.
