PHILADELPHIA, Pennsylvania - Hundreds of police officers surrounded a building in North Philadelphia on Wednesday, after a drug raid turned into a shoot-out.

Two officers who arrested suspects at the building were trapped inside the building, in the Tioga section of the city with the people they had arrested, however they were safely evacuated by a SWAT team towards the end of the operation.

Another person in the building opened fire on police resulting in the shoot-out. Six Philadelphia police officers were shot and trushed to local hospitals for treatment. Police say their injuries are not life-threatening. They were wearing body armour, and all six have now been released from hospital.

"Suspect is still firing. SIX (6) PPD Officers shot - at area hospitals with non life threatening injuries. Additional officers also receiving treatment for non-gunshot injuries. Continue to avoid area. Situation is active and ongoing," Philadelphia police said in a tweet during the operation.

"Officers are attempting to communicate with the shooter; imploring him to surrender and avoid further injuries," a post a few minutes later said.

Later in the day the man is believed to have surrendered himself to police. The SWAT team then began clearing the house.

Police asked onlookers to stay away from the area. They also asked media personnel and anyone else to not use drones during the operation.

Philadelphia Mayor Jim Kenney visited the six police officers in hospital prior to their release. "It has been a traumatic experience for them, " he said. He said there was obviosuly a concern, and a little anger, that someone had all the weapon that was used, but said police would get to that, right now the focus was on the welfare of the six injured officers.

"Tonight is another reminder of the selfless sacrifice of law enforcement and first responders," Pennsylvania Governor Tom Wolf said in a statement released on Wednesday night. "We are praying for a peaceful resolution and the recovery of all those injured. We must remain committed to combatting violence and getting dangerous weapons out of our communities," he said.

(Photo credit: Matt Rourke, AP).