Police in Newfoundland are investigating after someone let thousands of mink escape from a mink farm.

Employees at the farm in the town of Harcourt say they can't understand why someone let between 5,000 and 6,000 mink out of their cages over the weekend. By Sunday about half had been recovered, but there are fears many have already been killed on local roads.

"They were all running rampant, like rats going everywhere," says Michael Lyver, a local farmer. "There were mink all over the road dead, people running over them from the time they got out."

Lyver says that area farmers also killed some of the mink because they had attacked livestock. Local farmers said it was a shame to have killed what they described as beautiful animals. They noted that whoever unlocked their cages didn't have their best interest at heart. Employees at the Harcourt Mink Farm say that whoever was responsible went through a lot of trouble to release the animals from the facility that holds as many as 30,000 mink.

"It would be time consuming to walk down the barns," says Pauline Lambert, a supervisor at the farm. "The barns are fairly long. You have to go down and open every single latch to let them out. Whether there was more than one person involved, I don't know."

Wildlife officials fear the escaped mink will jeopardize the area's natural habitat.

"It causes a bit of a mess," says Hugh Whitney, a provincial veterinarian. "There's risks to wild animals in the area that would be out-competed by the mink ... there could be domestic animals that could be impacted. I think you've already seen cases of back yard poultry, ducks, chickens, geese (that were) targets for mink."

Police are still in the early stages of their investigation and don't have any suspects. They say the mink don't pose a danger to humans but are warning residents not to try to catch the animals. Licensed trappers, however, are encouraged to help recapture the mink. They'll receive a $50 reward for every mink they turn in. About 1,000 mink were still on the loose on Sunday.

The provincial government had placed restrictions on the provincial mink industry earlier this year. There were reports that some of the mink suffered from Aleutian disease, which can destroy animal populations or effect their reproduction.

With a report from NTV's Carolyn Stokes