Man arrested after knife attack outside Buckingham Palace

A man was arrested on Friday after attacking police with a knife outside Queen Elizabeth II's Buckingham Palace residence in London, police said.The attacker, believed to be aged in his early twenties, stopped his car near a police vehicle outside the world famous palace at around 8.35pm (1935 GMT), according to a Metropolitan Police statement.The officers required hospital treatment, according to police, who said it was too early to say whether the attack was an act of terrorism.