LONDON: A 26-year-old sword-wielding man attacked and wounded three police officers outside Buckingham Palace in London before being arrested, prompting Scotland Yard to launch a terror investigation.
The man initially held on suspicion of grievous bodily harm (GBH) and assault on police has now been re- arrested under the UKs Terrorism Act 2000, the Metropolitan Police said.
"A car deliberately drove at a police van and stopped in front of it in a restricted area on Constitution Hill near Buckingham Palace. The officers, who were unarmed police constables and from Westminster borough, got out of the van and approached the car, a blue Toyota Prius," the police said.
"As they challenged the driver, who was the only occupant in the car, he reached for what we now know to be a four-foot sword which was in the front passenger foot well," it said.
During a struggle, three officers sustained minor injuries. The man, who repeatedly shouted Allahu Akbar, was incapacitated with tear gas.
Two of the officers were taken by ambulance to hospital with minor cuts and discharged a short time later. The third officer did not require hospital treatment.
The suspect was taken to a London hospital for treatment of minor injuries and has now been taken to a central London police station for questioning.
"No members of the public at the scene are believed had any interaction with the arrested man. There are no other reported injuries," the Met Police said.
Queen Elizabeth II and other members of the royal family were not in Buckingham Palace at the time.
The 91-year-old monarch is at Balmoral Castle in Scotland and other senior members of the royal family are also away during the summer holiday season in the UK.
A Palace spokesperson said the summer opening hours and tours of the Queens London residence will go ahead on schedule, adding that it will be "business as usual".
Commander Dean Haydon, the head of the Met's Counter Terrorism Command, said, "Officers from the Counter Terrorism Command are now investigating and searches are being carried out in the Luton area today.
"We believe the man was acting alone and we are not looking for other suspects at this stage. While we cannot speculate on what the man was intending to do - this will be determined during the course of the investigation - it is only right that we investigate this as a terrorist incident at this time," he said.
Eyewitnesses have reported seeing a sword-like weapon in the suspects car. The man had stopped his car in a "restricted area" when police saw the weapon.
The area was surrounded immediately by armed police and other security services and tourists were ushered away from the area.
Europe is on high alert following a spate of recent terror attacks.
A terror cell launched an attack on Barcelona's famous Las Ramblas street last Wednesday, and at a nearby seaside town, leaving 14 people dead.
On Saturday night in Brussels, a man armed with a machete attacked a group of soldiers.
He was shot dead at the scene, while two soldiers were not seriously injured.
Britain has also been the scene of a series of terror attacks this year alone.
In March, a terrorist drove a car into pedestrians on Westminster Bridge in London, killing four people.
Khalid Masood then ran into the grounds of the Parliament, where he fatally stabbed an unarmed police officer.
He was shot dead by an armed officer.
A concert by pop star Ariana Grande in Manchester was attacked by a terrorist in May.
Suicide bomber Salman Ramadan Abedi detonated a shrapnel-laden homemade bomb at the entrance to the concert, leaving 23 dead and 250 injured.
In June, three terrorists in a van drove into pedestrians on London Bridge and then ran to Borough Market, where they stabbed people.
Eight people were killed and the three terrorists were shot dead by police.