A police officer is seriously injured in hospital after he was stabbed near a pub in east London.

Police swarmed the area after the plain clothes officer was knifed in Bow on Tuesday night.

Medics raced to the scene of the attack near to the Bow Bells Pub in Bow Road at about 9.20pm.

Scotland Yard said a teenage boy had been arrested on suspicion of attempted murder and a knife was recovered at the scene.

The Tower Hamlets borough police Twitter account said a police officer had been "seriously injured" and advised the public to avoid the area.

The officer - who was on duty at the time of the attack - was rushed to a hospital in east London.

Update Undercover police officer stabbed three times in stomach near Bow pub

Photos posted on social media showed scores of emergency services vehicles parked along the road and a police cordon in place.

London's Air Ambulance was also scrambed to the scene.

A woman, who was having a drink inside the Bow Bells, described seeing police and paramedics everywhere and said officers requested the pub lock its doors after the attack.

She told the Standard: "We aren't allowed out of the pub. We've seen someone being wheeled away with what looks like a stab wound."

Joe Coules posted on Twitter: "Police Officer stabbed on Bow Road. Explains all the sirens and why the helicopter is circling."

A witness, who asked not to be named, told the Standard: "Teams of police are scanning the area on foot. Dozens of them.

"At least one police helicopter has been circling in the vicinity."

Andy Higson tweeted: “A huge number of police at Bow Church DLR. Main road completely closed.”

Sarah Collings tweeted: “Bow Road closed with lots of police cars and tape - no buses.”

Peter Jones shared a picture of the police cordon and said: “Bow Road closure. 10pm.”

Liam Young wrote: “Huge police presence at Bow Church DLR. Helicopter above and road completely closed. Best to steer clear."

The Tower Hamlets borough police account posted on Twitter: “Police officer seriously injured in Bow Road, please avoid the area.”

A Metropolitan Police spokesman said: "A plain clothes police officer has been stabbed whilst on duty in Bow Road, near Bows Bell Pub at 9.20pm on Tuesday, November 22.

"London Air Ambulance and London Ambulance Service have attended and the officer has been taken to an east London hospital in a non-life-threatening condition.

"One male has been arrested on suspicion of attempted murder. A knife has been recovered.

"Enquiries are ongoing.

"At this early stage, this incident is not being treated as terrorist related."