The report says two pieces of information came to MI5 indicating possible criminal activity by Abedi, but this wasn't judged to be related to possible terrorist acts.
The head of MI5, Andrew Parker, is believed to have briefed Cabinet ministers about the alleged terror plot on Tuesday.
Naa'imur Zakariyah Rahman, 20, and Mohammed Aqib Imran, 21, were due in court on terror charges on Wednesday.
Scotland Yard, military intelligence security service MI5 and West Midlands Police reportedly had been investigating the plot for "several weeks".
A plot to assassinate UK Prime Minister Theresa May has been foiled, Sky News reported on Tuesday.
United Kingdom authorities think they've arrested two men who plotted to kill Prime Minister Theresa May after "bomb (ing) their way into" her official residence, the Guardian reported.
Northern Kentucky's General Cable Corp. agrees to be acquired in $3B deal
It expects the deal to lift underlying earnings per share by 10-12 percent within the first year after it is finalised. Massachusetts-based Martingale Asset Limited Partnership has invested 0.02% in General Cable Corporation (NYSE: BGC ).
Model at heart of Britain's Cold War sex scandal dies
The scandal rocked Harold Macmillan's government and was thought to have hastened the end of the Conservative government. She is survived by her son James from her first marriage, Seymour from her second and a granddaughter.
130+ New Emoji (Some Reversible) Proposed for iOS 12
Presumably, this would allow users to customize their emoji's direction before sending them. Burge notes that the changing emoji directions is at "a pretty early stage right now".
Suicide bomber Salman Abedi detonated an explosive at an Ariana Grande concert that killed 22 people on May 22.
A man died in a terrorist incident at Finsbury Park mosque in north London in the same month - and, in September, an attempt to bomb a Tube train at Parsons Green station failed.
Stringent protective measures were first put in place in the 1970s, and were tightened during the 1980s when Irish republicans launched attacks on the British mainland. The device landed in the back garden.
The nearest the IRA got to killing a British prime minister was in 1984 when they targeted the hotel Margaret Thatcher and top officials were staying in for that year's annual Conservative party conference in Brighton on Britain's south coast.