A police officer was stabbed outside an east London railway station on Friday night.
British Transport Police (BTP) said the male officer was approached by a suspect outside Ilford Station and attacked with a knife at around 9.45pm.
He was taken by ambulance to hospital for treatment for his injuries, which are not thought to life-threatening.
A man has been arrested over the incident, BTP said. It is understood that counter-terrorism police are not involved at this stage.
Witnesses described seeing the bloodied officer outside the station as it was put on “complete lockdown”.
One tweeted: “At Ilford station… just come outside and all I see is someone on the floor, blood and police.”
Footage shared on social media showed a man being restrained on the floor as more officers arrived.
The incident comes amid concerns of an increase in attacks on police officers amid a rise in violent crime across London.
The police are appealing for anyone who saw what happened to get in touch.
Following a recent incident where an officer was kicked into a road, close to the path of a bus, Metropolitan Police Federation Ken Marsh called for officers to be given greater support.
He previously warned of a “breakdown in society” after two officers were attacked as they tried to apprehend a suspect in Hackney.
“There is an element of people out there who just have no respect whatsoever and don’t care,” he said.
“They don’t care about their actions, don’t care how they behave and don’t care about the consequences and we are left to face that twenty-four hours a day seven days a week.”