It happened between 5pm on Saturday, June 4, and 9.15am this morning in West Park, in Herrington. The offender broke in, found keys to a gun cabinet and stole weapons that were inside.
The guns stolen are a .22 cz2452 bolt action rifle serial number 71a477 with a sound moderator fitted, a Hatsun semi automatic shotgun serial number 393314, a Lamber double barrelled up and under 12 bore shotgun serial number 278006, and a Webley vulcan air rifle with scope and silencer.
Officers are carrying out inquiries into the burglary and are appealing for witnesses. The area overlooks a park and farmland and it is believed there were a number of people walking their dogs at the time and police are keen for them to get in contact.
Detective Sergeat Steve Wallace said: "It is important we find these firearms as soon as possible before they fall into the wrong hands and I would urge anyone who was in West Park or the surrounding area this morning to come forward and speak to us.
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"If any gun dealers have been offered similar firearms for sale we would also ask they get in contact."
Anyone with information is asked to contact Northumbria Police on 101 quoting reference 208 060616 or Crimestoppers anonymously on 0800 555 111.