PORTSMOUTH, Va. (WVEC) -- Mission K9 Rescue brought in reinforcement to search for Darja, the 4-year-old missing Belgian Malinois retired explosive detection dog from Portsmouth.

Darja's brother, Kilo, has now joined the search for his sister, according to Mission K9 Rescue's Facebook page.

Darja went missing on Dec. 2 around 6 p.m.

Frankie Rivas, Darja's owner, left her with a friend when she had to leave town.

Rivas said she believes the dog missed her and went looking for her when she jumped the fence.

Darja, last seen wearing a red collar, went missing from the Shae Terrace neighborhood.

The dog is described as "super sweet, but she may be timid."

Darja spent most of her life in a working contract kennel in Kuwait. After issues with the kennel went viral, Darja was brought back to the U.S. along with nine other dogs. Rivas adopted Darja in September and the two have been close ever since.

If you see Darja, you are asked to call Frankie at 763-257-9367.

Mission K9 Rescue is now offering $2,000 in exchange for finding Darja. The reward previously was $500.