Police were forced to call for back up after an 18-year-old man seriously assaulted an officer.
An Islington police officer was left with "GBH type injuries" after a teenager deliberately rode his bike into him.
The teen then repeatedly punched the officer in the face, according to police.
A Barking and Dagenham MPS spokesman told the Standard they were called to assist in arresting the teen last night.
He said: “The 18 year old male had seriously assaulted an Islington officer earlier in the week, causing GBH type injuries having rode a bike into him and repeatedly punching him to the face.
“The suspect again became violent and the officers had to call for urgent assistance via pressing their panic button on their radio which alerted everyone to respond to their location."
Officers eventually detained the suspect at his home address on Cooke Road, Barking.
The 18-year-old was taken to an east London police station where he remains in custody.
