A gunman who opened fire on police as they were issuing a drug warrant in Philadelphia is in police custody, authorities said.

The gunman wounded six officers, triggering a standoff that continued into the night.

Philadelphia police Sergeant Eric Gripp, who had been tweeting updates during the incident, confirmed that the shooter had been taken into custody by police.

The drama began around 4:30 p.m. (local time) as officers went to a semi-detached home in a north Philadelphia neighbourhood to serve a narcotics warrant.

The operation “went awry almost immediately,” Philadelphia Police Commissioner Richard Ross said.

Many officers “had to escape through windows and doors to get (away) from a barrage of bullets,” Ross said.

The six officers who were struck by gunfire have been released from hospitals, Sergeant Gripp said.

Two other officers were trapped inside the house for about five hours after the shooting broke out. The were freed by a SWAT team after darkness had descended on the area.

UPDATE: Suspect is in custody. SWAT is still clearing the house

— Eric Gripp (@PPDEricGripp) August 15, 2019

Three people that officers had taken into custody in the house before the shooting started were also safely evacuated.

“It’s nothing short of a miracle that we don’t have multiple officers killed today,” Ross said.

Throughout the standoff, scores of police outside tried to talk down the shooter, who took sporadic aim at officers.

Live video from news stations showed a massive police presence in a neighbourhood, with dozens of police cars and officers, many with guns drawn.

A witness told NBC “I heard ‘shots fired, shots fired’ … a gentleman was on the second floor apartments. He started shooting out and everybody started running. They started barricading everything at once… Every officer ran; it was really serious.”

The Bureau of Alcohol, Tobacco, Firearms and Explosives said numerous agents had converged on the scene to assist Philadelphia police.

US President Donald Trump was briefed on the shooting, officials said.

Philadelphia Mayor: “Our officers need help. They need help. They need help with gun control. They need help with keeping these weapons out of these people’s hands.” https://t.co/0Z5DJDEsnH pic.twitter.com/ZskSqrKYLf

— CBS News (@CBSNews) August 15, 2019

Philadelphia Mayor Jim Kenney said he was thankful that officers’ injuries weren’t life-threatening.

“I’m a little angry about someone having all that weaponry and all that firepower, but we’ll get to that another day,” Kenney said.