Samalut, Egypt (CNN) -- A policeman fatally shot a Christian man and wounded five other Christians Tuesday in an attack on a train in Egypt, officials said. The incident occurred at about 5 p.m. when a man walked onto the train, which was stopped in the station at Samalut, about 200 kilometers south of Cairo, said Maryanne Nabil Thaki, 29, one of the victims. She said she was seated with her sister, Maggie Nabil Thaki, 25, their 52-year-old mother, Sabah Sinot Suleiman, and Maggie's fiance, 26-year-old Ehab Ashraf Kamal. They were en route to Cairo to buy an engagement ring, Maggie Thaki said.NEW: Deputy policeman arrested in shootingsIncident occurred Tuesday evening on a train south of CairoFamily was en route to Cairo to buy an engagement ringRelations between the Christian minority and Muslim majority within Egypt are tense 
 Question:All five were to be flown to _ for further treatment, a hospital employee said.
Cairo