Knife attacker slashes man in London "terrorist incident"

By James Davey and William James LONDON (Reuters) - A knife attacker slashed a man at an east London metro station, reportedly screaming "this is for Syria", in what police described as a terrorist incident, prompting the government to urge Britons on Sunday not to be intimidated by the attack. A pool of blood near the ticket barriers at the Leytonstone Underground station, about six miles (10 km) east of central London, could be seen in footage posted on Twitter that also showed the suspect con