CAIRO - A group of Muslims set fire to seven houses belonging to Christians and stripped a woman naked in southern Egypt after rumors that her Christian son had an affair with a Muslim woman, the local church and witnesses said.The incident took place on May 20 in the southern province of Minya, the local Coptic Orthodox church said in a statement.The Christian man fled with his wife and children on May 19, said Ishak Ibrahim, a human rights advocate at the Egyptian Initiative for Personal Rights. He told Reuters the man's parents went to the police, fearing for their lives.The next day a group of around 300 Muslim men set fire to and looted their house and stripped the mother naked out on the street. They set fire to and looted six other houses, eyewitnesses told Reuters."They burned the house and went in and dragged me out, threw me in front of the house and ripped my clothes. I was just as my mother gave birth to me and was screaming and crying," the woman, who requested anonymity, told Reuters.Coptic Orthodox Pope Tawadros II called for calm and restraint in a statement issued on Thursday. He said he was pursuing the matter with Egyptian officials and that he had spoken to the woman and all those whose homes were attacked.The 70-year-old woman accuses three Muslim men of stripping her and dragging her in front of her house, her lawyer Ehab Ramzi told Reuters.Security sources said police arrested five men in connection with the incident and that the public prosecution had ordered their detention. The prosecution ordered the arrest of 18 others, the security sources added.Ten members of parliament put forward a motion to cross examine Interior Minister Magdi Abdel Ghaffar over the incident.Orthodox Copts, who make up about 10 percent of Egypt's 90 million people and are the Middle East's biggest Christian community, have long complained of discrimination under successive Egyptian leaders.Minya's governor said that authorities would not accept any "infractions of irresponsible actions" on the part of Muslims against their "Christian brothers."