A police officer has been stabbed in the back and neck at an airport in Michigan, police say.
The officer is in hospital recovering. "Please keep the officer in your prayers," said Michigan State Police on Twitter.
The Bishop International Airport in Flint has been evacuated and additional officers have been stationed at city hall, officials say.
The officer appears to have been targeted, police tell local media.
Local media report that the officer is Lieutenant Jeff Neville, who is now in a stable condition.
One suspect is in custody.
The incident took place shortly after 09:00 local time on Wednesday.
The FBI are leading the investigation, in partnership with airport and local law enforcement agencies.
Flint Mayor Karen Weaver said in a statement: "My thoughts and prayers are with all of our law enforcement officers who work to service and protect us each and every day.
"I want the public to know that several agencies are involved and working to ensure the situation is under control."
We are taking extra precautions just to be safe, she added.