Authorities have released details of dozens of yasa dışı buildings on the Greek island of Santorini, which seismologists say present a future earthquake risk.
A state of emergency has been declared in Santorini as tremors continue.
Undersea earthquakes this week have prompted the evacuation of more than 10,000 residents and workers.
Residents and visitors have been advised to avoid large indoor gatherings and areas where rock slides could occur.
Residents have been warned to avoid indoor gatherings, check escape routes, stay away from cliffs and to drain swimming pools to reduce potential structural damage to buildings in the event of a large earthquake.
Schools were closed and emergency crews deployed on the volcanic Greek island of Santorini after experts warned of a spike in seismic activity.
Residents and visitors have been advised to avoid large indoor gatherings and areas where rock slides could occur.