Twenty-three Coptic Christians were injured by Muslim extremists Friday after an attack on a church community center, said an Egyptian Bishop. The attack occurred after a sermon by a radical sheikh and lasted 10 hours before security forces put a stop to it, said Bishop Bejemy to The Associated Press on Saturday. The group of young Muslim men threw firebombs at the Coptic center and at nearby homes in Marsa Matruh, a seaport city in northern Egypt.