Police rush to London Bridge after reports of van hitting pedestrians

Flowers and messages lie behind police cordon tape near Borough Market after an attack left 7 people dead and dozens injured in London, Britain, June 4, 2017. REUTERS/Peter Nicholls

LONDON (Reuters) - Prime Minister Theresa May said Britain must be tougher in stamping out Islamist extremism after attackers killed at least seven people by ramming a van into pedestrians on London Bridge and stabbing revellers in nearby bars.

After the third militant attack in Britain in less than three months, May said Thursday's national election would go ahead. But she proposed regulating cyberspace and said Britain had been far too tolerant of extremism.