Two British police officers suffered minor injuries while arresting a man with a knife outside Buckingham Palace Friday evening.
In a statement, the Metropolitan Police said the officers stopped the man on the Mall, a major thoroughfare connecting the palace to Trafalgar Square, at 8:35 p.m. local time after they spotted a large knife in his car.
The statement did not specify how the officers were injured, saying only that they were hurt "during the course of detaining" the suspect, who is believed to be in his 20s.
Several witnesses told Sky News they saw a man being "wrestled to the ground" as armed police responded to the scene.
The unidentified man was arrested on suspicion of grievious bodily harm and assault on police. The officers were treated at the scene and no other injuries were reported.
A large number of police vehicles could be seen in the road outside the palace. There was no immediate indication the incident was related to terrorism.
Buckingham Palace is the London residence of Queen Elizabeth II and his her administrative headquarters. However, the queen usually spends August in Scotland at her Balmoral estate with family members.
Police stepped up patrols around major U.K. tourist sites after attacks with vehicles and knives earlier this year on Westminster Bridge, which is near Parliament, and London Bridge.
Buckingham Palace, which is surrounded by tall gates, has seen past security breaches. Last year, a man convicted of murder climbed a wall while the queen was at home, and was detained in the grounds.
In 1982, an intruder managed to sneak into the queen's private chambers while she was in bed. Elizabeth spent 10 minutes chatting with him before calling for help.
A palace spokeswoman said the palace did not comment on security issues.
The Associated Press contributed to this report.