Oklahoma labor commissioner killed in restaurant stabbing: local media
Police officer at a crime scene (Shutterstock.com)

The Commissioner of Labor for Oklahoma, Mark Costello, was killed in a stabbing at a fast food restaurant in Oklahoma City on Sunday, local broadcasters reported, citing unnamed sources.

Police declined to confirm that Costello was the victim but said one family member stabbed another family member at least four times with a knife after the pair agreed to meet at the restaurant following a fight earlier in the day.

"So sorry to hear the tragic news about Mark Costello," Oklahoma City Mayor Mick Cornett said in a Tweet.

U.S. Senator James Lankford, of Oklahoma, said in a statement: "My family is stunned and deeply grieved to hear of the tragic death of Labor Commissioner Mark Costello. Mark was passionate about our nation, conservative fiscal principles, and the people of our state."

Local broadcaster News 9, citing unnamed sources, reported that Costello was stabbed to death Sunday evening at a northwest Oklahoma City fast food restaurant.

Local ABC-affiliate Channel 8, also citing multiple unnamed sources, said it was Costello who was stabbed and that he could be seen stumbling out of the restaurant afterward.

Reuters could not independently verify the reports of Costello's death.

Police later arrested a man suspected in the attack, police said.

The victim was taken to a nearby hospital, where he was pronounced dead, police said.

Costello was first elected state labor commissioner in November 2010, according to a state website. He and his wife, Cathy, have been married for 33 years, and have five children.