A moderate earthquake shook Turkey's capital and caused panic in a nearby town early Thursday. There were no reports of any damage or injuries. The quake centered in the town Cubuk, just outside Ankara, at 12:22 a.m. (2122 GMT) and had a preliminary magnitude of 4.6, the Istanbul-based Kandilli Observatory said. It was followed by a magnitude 3.4 aftershock. Anxious Cubuk residents ran into the streets following the quake, but there were no reports of any damage or injuries, the semiofficial Anatolia news agency said. Quakes are frequent in Turkey, much of which lies atop the active North Anatolian fault. Two devastating earthquakes killed about 18,000 people in northwestern Turkey in 1999.