Six Philadelphia police officers were shot on Wednesday in a drug raid on a home, and at least one shooter continued to fire on officers barricaded inside, according to police and local media.
Philadelphia police said the officers did not have life-threatening injuries.
Local television station Fox 29 said six officers were taken to two local hospitals, while two other officers were injured in a car accident while responding to the shooting.
NBC 10 said a male suspect was in a building in north Philadelphia and exchanging gunfire with police. "Suspect is still firing. STAY OUT OF THE AREA," police tweeted.
Fox 29 reported that two drug squad officers were holding individuals they had arrested while serving a warrant, with both officers barricaded inside the building with the suspects.
The shooter was firing into the ceiling of the structure and outside, Fox 29 reported, citing a senior police official.
Television images showed hundreds of police surrounding the building, many with guns drawn, with stations saying a SWAT team was negotiating with the shooter.