A moped pillion passenger pointed a gun at officers in a van as they took a suspected thief into custody.
The threats were made after colleagues had foiled a raid on a mobile phone shop during the early hours of this morning.
Two officers in a passing patrol car came across two crooks inside the shop while another waited on a moped outside in Peckham, south east London..
One of the officers managed to detained a 24-year-old man while his colleague tried to tackle the other two.
But they jumped on the moped, rode around the officers making threats and kicking them and allowing their accomplice to escape.
As the moped rode off the officers gave chase to the accomplice on foot and with the help from back-up was arrested after being Tasered.
The accomplice was taken to his Croydon home so it could be searched but when the police van left a moped drew level with the van and the gun was pointed at them.
But no shots were fired and the officers drove to a south London police station with the suspect.
The latest example of lawless London came two days after officers were kicked as they tried to arrest a suspect inside a McDonalds in Dalston.
Scotland Yard is now trying to trace the “dangerous” moped riders.
Simon Messinger, Central South Area Commander, said: “This once again demonstrates the bravery of officers who put themselves in harm’s way every day in order to protect the public.
“Fortunately the officers only received minor injuries and, thanks to the rapid support of colleagues, one of the suspects was detained.
“However, two suspects remain outstanding, and these are clearly reckless and dangerous individuals. Our priority now is to identify and arrest them. “
A police spokesperson said: “A man has been arrested and enquiries are ongoing to trace two outstanding suspects after police intervened to stop a burglary at a mobile phone shop in Peckham.
“Officers were assaulted while making the arrest, and a firearm was pointed at them as they made further enquiries after the incident.
“At approximately 1.20am on Wednesday, 29 August, response team officers who were on patrol in Peckham came across a burglary in progress at a mobile phone shop in Rye Lane.
“The two officers, who were in a marked police car, saw two suspects inside the shop and a third waiting outside on a moped.
“One suspect – ‘A’ aged 24 – was detained at the scene by an officer, while his colleague attempted to detain the other two – ‘B’ and ‘C’ – who got on the moped.
“The suspects on the moped used this to encircle officers, threatening them and pushing and kicking them in the process.
“This resulted in ‘A’ making off on foot, while the other two males rode off on the moped. Neither officer was seriously injured.
“Suspect ‘A’ was pursued by the officers, and minutes later he was recaptured nearby by additional officers who had been called to provide urgent assistance.
“A Taser was discharged, and ‘A’ was arrested and taken away in a police van.
“Before taking him to custody, officers in the police van attended an address in Croydon along with ‘A’ to carry out a search under Section 18 of the Police and Criminal Evidence Act.
“Once the search was complete they left the address to take ‘A’ to the police station. While they were in the van, two males on a moped pulled up alongside the police van and pointed a firearm towards officers.
“Enquiries are ongoing to establish whether these two males were suspects ‘B’ and ‘C’.
“No shots were fired, and the officers drove away from the scene with ‘A’ who was taken into custody at a south London police station.
“Urgent enquiries continue to identify the other suspects involved.”
By Ben Gelblum and Tony Whitfield