A powerful earthquake shook Greece on Sunday and was felt as far away as the Middle East. Minor damage was reported in southern Greece, and authorities on the island of Crete said three people were slightly injured. The Athens Geodynamic Institute, which initially gave a magnitude of 6.4, later amended it to 6.9 and said the epicenter was located beneath the seabed, about 200 kilometers (125 miles) south of Athens and 20 kilometers (12 miles) east of the island of Kithira. "It was a very powerful quake which shook all of Greece. There have been dozens of aftershocks, four with a magnitude of 5," said institute head Giorgos Stavrakakis. "The quake occurred deep undersea and that's what saved us." The earthquake occurred at 1:34 p.m. and was felt as far away as in Cairo, Egypt, about 1,200 kilometers (745 miles) southeast of the epicenter, as well as in Amman, Jordan. Similarly, the Geophysical Institute of Israel reported that the quake was felt in Israel as well. The quake was felt across southern Italy - in particular around Naples and Sicily - but there were no reports of damage or injuries, Italian news reports said. Some people ran into the streets and others phoned civil protection agencies or the fire department seeking information. Clarice Nassif Ransom, a USGS spokeswoman in Washington, said scientists project that as many as six million people may have felt the earthquake. "This is an area which regularly gives out strong quakes so we are not surprised. But we don't expect any serious aftershocks," Stavrakakis said. Authorities on Kithira said the airport and about 50 old buildings had also been slightly damaged. "We've had some damage to old buildings but nothing serious has occurred, and we have no reports of injuries," said Kithira mayor Andreas Kalligeros. The US Geological Survey, based in Colorado, and the National Earthquake Information Center in Denver gave a preliminary magnitude of 6.7, while the University of Thessaloniki, which also has a geodynamic institute, reported a preliminary magnitude of 6.9. The reason for the discrepancies in magnitude was not immediately clear.