Local police say a 17-year-old launched himself at the flame as it passed through the English riverside town of Gravesend and has since been arrested. The runner swerved aside and the relay wasn't disrupted.
This year's torch relay has not been hit by the human rights protests that bedeviled the Beijing Olympic relay in 2008. But police are still ready to ward off attention-seekers who might try to attack the flame on its 12,800-kilometre journey.
The torch is due to arrive in London later Friday, when a Royal Marine will rappel with it from a helicopter to the Tower of London.