A still image of a surveillance video which shows the kittens being dropped off. (Facebook/Prince Albert SPCA)

Thirteen kittens died after being left outside of the Prince Albert SPCA inside two sealed, plastic containers.

The SPCA’s manager, Ashlee Bober, estimated that the kittens were between five and six months old. She said she showed up to work at 8 a.m. on Tuesday morning to find the bins at the door.

The organization posted surveillance footage on its Facebook page, which shows two people dropping off the containers at about 6 a.m. that morning.

“This is not OK,” reads the post.

Bober said the SPCA doesn’t always have the space to take in a number of animals at all times.

“If that is the case, the option isn’t to just dump them off at the front door,” she said, suggesting finding someone who can take care of them until the facility has the proper space.

Bober said to make sure your dogs and cats are spayed or neutered.

“That is probably going to stop this problem from happening, of having an abundance of kittens and puppies.”

She said Saskatchewan Animal Protection Services is working on the case. Anyone with information is asked to contact them at 306-382-0002 or toll-free at 1-844-382-0002.