Man wielding knife arrested near US embassy in Tokyo

The motive behind the attack was not immediately known.

Friday's attack comes days before US President Donald Trump's planned trip to Tokyo. Trump will meet with Japan's Emperor Naruhito and newly elected Prime Minister Sanae Takaichi during his October 27-29 stay in Japan, the government has said.

The Tokyo Metropolitan Police Department has mobilised up to an additional 18,000 personnel to bolster security for the visit, Kyodo News reported earlier this week.