Armed police warned crowds in the heart of London’s shopping center Friday to take cover inside buildings after gunshots were reported. Four main streets have been cleared of pedestrians and traffic: Oxford Street, Regent Street, Bond Street and Tottenham Court Rd. following a shooting incident that began inside Oxford Circus Tube station and continued on Oxford Street. Police have not confirmed whether the incident was terror-related or criminal, but have gone into anti-terrorist mode. No casualties have been reported, although medical responders are at the scene. Black Friday is one of the busiest shopping days on the London calendar.