Police in London have identified two of the three men they say took part in a terrorist attack that seven people dead and several more wounded over the weekend. Officials said Khuram Shazad Butt and Rachid Redouane used a van and large knives in the attack on London Bridge and elsewhere in the city. A third attacker is known by police, but his name has not been released. The Islamic State has claimed responsibility for the attack, in which all three terrorists were killed by police.