British police confirmed on Wednesday that the suicide bomber who killed 22 people at a Manchester concert was not acting alone.
Some of the victims had been making their way outside at the end of the Ariana Grande gig when Abedi detonated his "nuts-and-bolts" bomb.
"We are working closely and intensively with our British partners to probe possible terrorist networks and we have achieved important progress", deputy interior minister Abdelsalam Ashour told reporters.
After the deadliest attack in Britain since July 2005, police are hunting for accomplices whom they suspect helped Salman Abedi build the bomb that killed 22 people on Monday in a crowded concert hall in the northern English city of Manchester.
The leaks have opened a diplomatic row as the United Kingdom officials are said to be "furious" that their investigation was compromised when photos appearing to show debris from the attack appeared in the New York Times.
Among those taken into custody in Libya on Wednesday were the suspected bomber's father and his younger brother, the latter of whom confessed to knowing "all the details" of the attack plot, Libyan anti-terrorism authorities said.
Investigators in Britain were trying to track down a jihadist network suspected of having orchestrated the attack which also wounded dozens.
One man was arrested following raids in the Withington area while the other was arrested in the Manchester area, according to the police.
A Whitehall source described the second United States leak as "on another level", and told the BBC it had caused "disbelief and astonishment" across the British government. Britain's terror threat assessment has been hiked to "critical", the highest level, meaning an attack is considered imminent.
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Troops have been deployed to free up police officers for patrols and investigations, and on Thursday the British Transport Police said armed officers would patrol trains for the first time. A new cell is to be established at Nato's headquarters to improve "how we share intelligence, including on foreign fighters", Stoltenberg said.
A third relative, Abedi's older brother Ismail, was arrested in Manchester.
Who are the Manchester bombing victims?.
British officials were particularly angry over photos published by The New York Times showing remnants of a blue backpack which may have held the explosive.
Numerous victims of the attack were young.
"They wouldn't let you share bread with them", she said Abedi told her.
Meanwhile, the Queen visited Royal Manchester Children's Hopsital on Thursday morning to visit some of the injured as well as the emergency services.
"I think it's pretty disgusting", said Scott Lightfoot, a Manchester resident, speaking outside a train station in the city.
A woman looks at the floral tributes and messages left for the victims of the concert blast, during a vigil at St Ann's Square in central Manchester, England, Wednesday, May 24, 2017.
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