A man has been arrested after two police officers were attacked outside Buckingham Palace.
The Metropolitan Police said two male officers stopped a man who was carrying a knife, and were injured in the process of detaining him, Metro UK reports.
They suffered minor injuries and were treated by London Ambulance Service paramedics at the scene.
No one else was hurt in the incident that happened at about 8.35pm on Friday, police said.
Some eyewitnesses claimed the weapon used was a sword.
Police added that a man has been arrested on suspicion of grievous bodily harm and assault on police.
The Queen is not believed to be at the palace as she usually spends August at her estate in Balmoral.
A witness described seeing a man wrestled from a car by police having apparently driven his vehicle towards them.
Kiana Williamson said: ‘We turned up and there was one police van and one car, there was also a civilian’s car that had veered towards the police car.
‘They were trying to get the man out of the car, shouting, more police were arriving on to the scene and the man was fighting back.
‘I saw one injured policeman with an injury to his arm although it didn’t look severe.
‘He was being tended to by another officer.
‘The man had been restrained and looked almost unconscious by the side of the road.
‘I didn’t see the car driving but the car had been left at the side of the road and an eye witness had said that he had driven towards the police car.’
‘We then saw that police had expanded the cordon. It looks like the cordon is continuing to expand.’
Scotland Yard added that it is too early to know if the incident is terror-related.
More officers were sent to The Mall following the attack
A spokesperson for the Met said: ‘The man was stopped this evening by officers at the Mall outside Buckingham Palace in possession of knife.
‘During the course of detaining him, two male police officers suffered minor injuries to their arm.’
Enquiries are ongoing.