A strong earthquake with a preliminary magnitude of 5.7 shook a port city in western Turkey on Monday, sending terrified residents running from their homes but causing only minor damage, reports said. There were no immediate reports of injuries. The earthquake struck at 8:45 a.m. (0545GMT) and was centered in the Aegean Sea off the coast of Izmir, the Istanbul-based Kandilli Observatory said. Two aftershocks with preliminary magnitudes of 4.1 and 3.0 followed. The temblor collapsed the walls of some houses and shattered windows in the town of Urla, just west of Izmir, private NTV television said. Selcuk Karaosmanoglu, the mayor of Urla, told the Anatolia news agency that the quake toppled some chimneys in the village of Bademler and also caused cracks in some buildings in the town center. Gov. Oguz Kagan Koksal said there were no immediate reports of injuries and authorities were evaluating the damage across the province. In the provincial center of Izmir, Turkey's third largest city with a population of some 3 million people, some residents rushed into the streets in panic.