Mairead McCallion, who was 36, died in hospital on Monday after she was found with head injuries at a house in Castleview Court over the weekend.Police launched a murder investigation and a 50-year-old man has been arrested in Omagh. He is currently being questioned on suspicion of murder.Detective Chief Inspector Richard Harkness has appealed to the public for information.He said: "We are keen to speak with anyone who may have any information which could assist us and I would urge members of the community in Omagh to contact us. "We are interested in talking to those who knew or saw Mairead, not just in the days leading up to her death, but over the past number of years. "People may know something that could provide us with important information to enable us to get justice for Mairead. I can assure you that if you do come forward, your information will be treated in the utmost confidence."Information can be passed to police on 0845 600 8000.