A woman was tied up and locked in a bathroom by masked crowbar-wielding raiders who broke in to a house.
The PSNI said the woman, who is in her 20s, has been “badly shocked by her ordeal”.
She was confronted by the three men who forced their way into a house in the Craigmore Road area of Garvagh shortly before 6am on Saturday.
The thieves stole six legally held firearms and are believed to have then made their getaway in a vehicle.
Detective Inspector Bob Blemmings, who is investigating the aggravated burglary, is appealing for anyone who was in the area at the time and saw any suspicious activity to contact CID in Coleraine or Crimestoppers.