Armed police opened fire outside the Ukrainian embassy in west London on Saturday morning following reports of a car "deliberately ramming" a vehicle used by its ambassador.
The Metropolitan police were called to the scene in Holland Park after a car crashed into Ukrainian ambassador Natalia Galibarenko's official vehicle, used for carrying out her duties.
The attack – which is not thought to be terror-related – took place at around 9.50am. According to a statement from the Ukrainian embassy, the car crashed into a number of parked vehicles before driving into Galibarenko's car.
When police arrived at the scene, the suspect drove into officers prompting them to open fire, the Met said. Eyewitnesses reported hearing up to 10 gunshots.
A taser was also used.
A man in his 40s has been arrested. He has been taken to a central London hospital as a precaution.
In a statement, the Ukrainian embassy said: "Around 10am on Saturday 13 April, the official vehicle of the Ambassador of Ukraine to the United Kingdom was deliberately rammed as it sat parked in front of the Embassy of Ukraine’s building.
"The police were called immediately, and the suspect’s vehicle was blocked up. Nevertheless, despite the police actions, the attacker hit the Ambassador’s car again. In response, the police were forced to open fire on the perpetrator’s vehicle. The culprit was apprehended and taken to a police station.
"No one of the Embassy staff were injured. The police are investigating the suspect’s identity and motive for the attack."
Chief Superintendent Andy Walker, from the Met's Specialist Firearms Command, said: "As is standard procedure, an investigation is now ongoing into the discharge of a police firearm during this incident.
"While this takes place, I would like to pay tribute to the officers involved this morning who responded swiftly to this incident and put themselves in harm's way, as they do every day, to keep the people of London safe."
The Directorate of Professional Standards, which investigates the conduct of police officers, has opened an investigation.