San Francisco police are warning photographers and tourists to pay close attention to their surroundings after a rash of robberies targeting cameras.

The police department is investigating five robberies in the past week where thieves stole camera equipment at or near tourist destinations. One of the cases included a photographer being robbed at gunpoint.

Police said they have made two arrests in one case.

"I think criminals are looking for other things they can easily access," San Francisco police Capt. Greg McEachern said. "Looking at things like cameras, backpacks that contain wallets and iPads and so forth."

Police suggest owners should have on file camera serial numbers. They also said owners should write their drivers license numbers inside the camera's battery compartment just in case the camera is lost or stolen.