Seven people were killed and at least 48 injured in terrorist attacks in central London on Saturday, British authorities said, prompting Prime Minister Theresa May to vow a tough response to Islamist extremism.A van was driven at pedestrians on London Bridge shortly after 10 p.m. Saturday, before three assailants emerged from the vehicle and went on a stabbing rampage at nearby Borough Market. Police shot and killed all three assailants, they said.(Getty)Twelve people were later arrested in Barking, east London, and several locations were searched in connection with the attack, the police s…READ FULL ARTICLE