PORTLAND, Maine (AP) Three police officers were injured while taking a gun from a convicted felon in an incident that drew an unruly crowd, officials said.

A dozen or so people taunted and cursed at the officers and a 17-year-old bystander was arrested. The police chief described the episode Sunday evening as the latest in a pattern of aggressive behavior toward police this month.

“It’s disheartening. It’s demoralizing to our officers,” Portland Police Chief Frank Clark said.

The latest incident began when police noticed that a 21-year-old man had a gun in his waistband.

That man fought with officers who arrested him for being a felon in possession of a firearm, and a hostile crowd quickly grew. The teenager challenged the officers to a fight, threw a metal container at the hood of a police car and shoved an officer.

The incident came after a group aimed fireworks at officers on July 5 in Kennedy Park.