Sky News Headline says:Some of the suspects being held in connection with the London and Glasgow terror plots were known to MI5 before the attacks took place, it has emerged. Up to four of those detained are believed to have appeared on the MI5 database. Whitehall sources confirmed the Security Service had established "linkages" with a number of the individuals. They said it was not clear how much was known about them but MI5 had been able to pass on valuable information to police. According to reports, the known suspects had 'crossed MI5's radar' during previous anti-terror probes but were considered low priority.
