LONDON: A man arrested under the Terrorism Act after deliberately driving at police outside Queen Elizabeth II's Buckingham Palace residence in London had a "four-foot sword" in his car, police said on Saturday, reports AFP.

Upon being challenged by officers, the 26-year-old attacker "reached for what we now know to be a four-foot sword which was in the front passenger foot well," the police statement said.

"The man, who repeatedly shouted Allahu akbar (God is greatest), was incapacitated with CS spray". The assailant stopped his car near a police vehicle in a restricted area outside the world famous palace at around 8:35pm (1935 GMT) Friday, according to a Metropolitan Police statement.

Three unarmed officers were injured during the course of detaining the man, two of them requiring hospital treatment.

Initially arrested on suspicion of causing grievous bodily harm and assaulting police, he was later arrested under the Terrorism Act 2000.

Originally from Luton -- a city 30 miles (50 km) north of London -- the assailant was then taken to a London hospital for treatment of minor injuries before being taken to a central London police station for questioning.