A strong earthquake with a preliminary magnitude of 6.5 struck southwestern Greece on Sunday, killing at least two people, injuring 90 and flattening dozens of homes, authorities said. It was Greece's first fatal earthquake since 1999, when a 5.9 magnitude quake near Athens killed 143 people and left thousands homeless. Sunday's quake struck at 3:25 p.m. near the port city of Patras, about 200 kilometers west of Athens in the northwestern Peloponnese, and had a shallow epicenter, the Athens Geodynamic Institute said. It was felt as far away as southern Italy. Two people were killed and 90 were injured, most of them lightly, the Interior Ministry said. By nightfall, six of the injured remained hospitalized. One of the dead was a woman who was lightly injured, but died later in hospital of a heart attack, while the other was a man killed by a falling pergola outside his home in the village of Kato Ahaia. With dozens of houses destroyed or severely damaged, the government said it would give $4,680 as aid to anyone who had lost their primary home in the quake. Frequent aftershocks rattled already frightened residents, and seismologists urged caution, particularly around buildings that damaged in the initial quake. "We are watching the seismic activity with great attention. We are not yet certain that the danger is completely over," said Athens Geodynamic Institute director Gerasimos Papadopoulos. Although it was unlikely that there would be a stronger quake, "there is still concern. ... For this reason, and because strong aftershocks are expected, great care must be taken." Military rescue helicopters and transport planes, and a specialized Air Force rescue crew were placed on standby, the National Defense General Staff said. The quake damaged the air traffic control tower of the Andravida military airport, but a secondary tower was being used and the airport remained open, the general staff said. Two families - seven people in total - were rescued after being trapped in collapsed houses in the village of Fostaina, about 30 kilometers south of Patras, and in the village of Vartholomio, authorities said. Television footage showed rescue crews pulling a 9-year-old girl from beneath the rubble of her house in Fostaina after a two-hour rescue effort and placing her on a stretcher. The girl suffered only slight injuries. "I have seen nothing like that in my lifetime," an 88-year-old woman in Kato Ahaia, told state-run NET television. "When the earthquake began, I was in bed. I tried to leave but fell down. I crawled on my knees to the front door." She said neighbors got her out of the house. Teams of rescuers from 17 Balkan and Mediterranean countries who had just arrived in Greece for a disaster response training exercise joined Greek colleagues in rescue efforts. Hours after the quake, terrified residents stayed away from their homes, gathering in village squares and outdoor coffee shops. Local authorities cordoned off unsafe buildings in villages, and ordered all schools in the area to remain shut Monday. The Tourism Ministry and Greek tourist board said no damage had been reported in any of the area's hotels and that no holiday-makers had been hurt. Interior Minister Prokopis Pavlopoulos said the damage was relatively light. "An initial assessment shows we don't have widespread damage," the interior minister said. "The consequences of an earthquake of this intensity and at this depth were relatively limited." The fire service said a landslide cut off part of the Corinth to Patras highway. The U.S. Geological Survey gave a preliminary magnitude of 6.1 for the quake, while the Athens Geodynamic Institute gave a preliminary magnitude of 6.5. Magnitudes often vary in the first hours or days after an earthquake. Greece is one of the world's most earthquake-prone countries, but most quakes cause no injuries.