Four women were removed by police from a block of flats in Barking, east London, on Sunday as police announced a total of 12 people from the area had been arrested in connection with Saturday's attack. The four women, whose faces were covered as they left the building, were escorted by officers into the back of two waiting police vans and then driven away, the photographer said. Three attackers drove a van into pedestrians on London Bridge before stabbing revelers nearby on Saturday night, killing seven people and injuring 48 others in what Britain called the work of militants engaged in a new trend of terrorism. The attack occurred five days ahead of a parliamentary election and was the third to hit Britain in less than three months. Prime Minister Theresa May said the election would go ahead as planned on Thursday. "It is time to say enough is enough," she said in a televised statement outside her Downing Street office, where flags few at half-mast. "We cannot and must not pretend that things can continue as they are," May said, calling for a strengthened counter-terrorism strategy that could include longer jail sentences for some offences and new cyberspace regulations. On Saturday night, police shot dead the three male assailants in the Borough Market area near London Bridge within eight minutes of receiving the first emergency call shortly after 10 p.m. local time. Eyewitnesses described harrowing scenes as the attackers' white van veered on and off the bridge sidewalk, hitting people along the way, and the three men then ran into an area packed with cafes and restaurants, stabbing people indiscriminately. Londoners fought back with whatever came to hand, in some cases hurling chairs and tables to ward them off. "It looked like he was aiming for groups of people," Mark Roberts, a 53-year-old management consultant, told Reuters. He saw at least six people on the ground after the van veered on and off the pavement. "It was horrendous." Gerard Vowles told Sky TV that he was on the street near the Southwark Tavern cafe, the scene of multiple stabbings, when he heard someone say: "I've been stabbed, I've been stabbed." "I thought they were joking," he said. He said he then saw a woman and man being stabbed. He recalled how he tried to distract the attackers. "As they left I was going ‘Oi, oi, cowards!" Vowles said. "I was just trying to get their attention by throwing things at them ... I thought if I throw bottles or chairs they can come after me. If I can get them to come to the main road then the police can stop them, they can obviously shoot them." — Agencies