LUXEMBOURG — European Union foreign ministers on Monday condemned the worst sectarian violence in Egypt since the ouster of Hosni Mubarak and told authorities to do more to protect religious minorities. "It is about time that the Egyptian leadership understands the importance of religious plurality and tolerance," German Foreign Minister Guido Westerwelle said, highlighting European displeasure following months of steadfast support. Condemnation of the violence was strong across the board. "It's very important that the Egyptian authorities reaffirm freedom of worship in Egypt," said British Foreign Secretary Wiliam Hague. EU foreign affairs chief Catherine Ashton said it was up to Egypt "to protect your people, whoever they are, wherever they come from or whatever belief or faith they have." At least 24 people were killed and more than 200 injured in Sunday night's violence in Cairo. Christian protesters say their sit-in demonstration at the state television building was attacked by thugs in plainclothes. The rioting lasted late into the night, bringing out a deployment of more than 1,000 security forces and armored vehicles to defend the state television building. "It is totally unacceptable that people, because they want to practice their Christian faith and life, are physically threatened. It is unacceptable," said Westerwelle. Egypt's official news agency announced that dozens of "instigators of chaos" were arrested after the deadly clashes between angry Christians, Muslims and security forces. Sunday's fighting was sparked by a recent attack on a church in southern Egypt.