FILE PHOTO: A Wendy's Co restaurant is pictured in Monrovia, California November 4, 2015. REUTERS/Mario Anzuoni

NEW YORK (Reuters) - A Wendy's WEN.O restaurant in Oklahoma is under fire after an employee video showing a mouse inside a bag of hamburger buns was widely shared online.

The Facebook video was filmed at a Wendy’s restaurant in Catoosa, Oklahoma, the employee, Sky Frame, said in a post. It showed a mouse peering out among the buns.

“Not only does Wendy’s now have mice - we have crew members who leave cigarettes all over the place. Don’t eat at Wendy’s in Catoosa,” Frame wrote on Facebook, alongside the June 14 video and a picture showing an unlit cigarette at a food prep station.

A Wendy’s spokesperson said the local health department visited the restaurant on Friday and found no violations.

“This is an isolated incident at the restaurant; it did not happen at the vendor or distribution levels,” the spokesperson said in a statement.

“Our franchisee is aware of this situation and is taking this matter very seriously. They immediately launched an investigation with their pest control vendor and internal quality assurance experts to ensure immediate and appropriate action is taken,” the spokesperson said.

Shares of Wendy’s Co, the fifth-largest U.S. fast-food chain by revenue, were down 0.84 percent in afternoon trading.