A powerful 6.3-magnitude earthquake struck off the Greek island of Crete Tuesday, the Athens Observatory said, with initial media reports suggesting no one was hurt.
The quake -- the second strong tremor to hit Greece's largest island in just over two weeks -- struck at 0924 GMT with an epicentre in the sea 405 kilometres (250 miles) southeast of Athens and 24 kilometres from the village of Zakros, the Observatory said in a statement.
It had a depth of less than nine kilometres, the observatory said.
Local media said it was felt on Crete and on the Dodecanese islands in the Aegean Sea, with worried residents gathering on the street. The neighbouring island of Karpathos was shaken by a 4.5-magnitude undersea quake minutes later.
"The epicentre is in the sea, far from inhabited places," Greek seismologist Gerassimos Papadopoulos told Skai radio.
Civil protection agency spokesman Spyros Georgiou told AFP that the Tuesday tremor had partially collapsed a village church and caused landslides on rural roads.
The civil protection agency said in a statement that Greek police land units and helicopters were patrolling the area, while the coastguard was on the watch for possible tsunami activity.
Papadopoulos added that the Tuesday tremor had a different epicentre than a strong 5.8-magnitude quake on September 27 which killed one person, injured nearly a dozen others, and damaged hundreds of buildings on Crete.
Over 3,000 homes were deemed unsafe following last month's quake, and dozens of businesses were knocked out. Many people are still staying in tents and containers.
Efthymis Lekkas, the head of Greece's quake protection agency, told Skai radio that the two earthquakes were not related.
Greece is located on a number of fault lines, and is sporadically hit by earthquakes.
The last deadly quake in the country occurred on March 3 in the central town of Elassona, killing one person, injuring 10 and causing major damage.
Last October, a magnitude 7.0 hit in the Aegean Sea between the Greek island of Samos and the city of Izmir in western Turkey.
Most of the damage was in Turkey, where 114 people were killed and more than 1,000 injured.
In Greece, two teenagers were reported dead on Samos.