Terror checks intensify as London attack enters election fray

Britain's Boris Johnson said Sunday the security services were stepping up monitoring of convicted terrorists released early from prison, as the London Bridge attack became embroiled in the election campaign.The prime minister revealed officials were scrutinising around 74 people with terrorist convictions who had been released early from prison like Usman Khan, who left jail last December and went on to stab two people to death in Friday's rampage.Khan, 28, was shot dead wearing a fake explosiv