A 6.3-magnitude earthquake struck central Italy early Monday, killing 20 people, including four children, Italian media reported. The quake destroyed many buildings, including older structures. Rescue operations were under way, with an unknown number of people trapped in rubble, CNN reported. The U.S. Geological Survey measured the quake at magnitude 6.3, conflicting with Italy's national institute for geophysics, which put the quake at magnitude 5.8. The earthquake struck at 3:32 a.m. (1:32 a.m. GMT Sunday) about 95 kilometers (60 miles) northeast of Rome. Damage was concentrated about 120 miles from the city of L'Aquila. Frightened residents awakened from sleep and rushed into streets. Tens of thousands of people were out in the streets, according to the mayor of L'Aquila. Part of the region is without electricity, and crews were checking for gas leaks.