Police hunting the terror network behind the Manchester Arena bombing have stopped passing information to the US on the investigation as a major transatlantic row erupted over leaks of key evidence in the US, according to a report.
The police, Downing Street and the Home Office refused to comment on the BBC report, but Theresa May will confront Donald Trump about the leaks - including crime scene photographs - when she meets him at a Nato summit in Brussels on Thursday.
The leaks included suggestions that bomber Salman Abedi's family had warned security officials he was dangerous.
There were also reports Abedi's parents were so worried about him being radicalised in Manchester that they got him to join them in Libya and confiscated his passport. It was apparently returned when he said he wanted to go on a pilgrimage to Mecca.
Home Secretary Amber Rudd has admitted Abedi, 22, was known to the security services "up to a point".
But further details have emerged about the UK-born bomber's radicalisation, and the warnings that were sounded, which will raise questions about why he was not more closely monitored.
Responding to the leak in the New York Times of crime scene photos showing bomb fragments and the backpack used by Abedi to conceal his device, the National Police Chiefs' Council said it "undermines our investigations and the confidence of victims, witnesses and their families".
But in the US, politicians were openly briefing the media on what they had been told about Abedi and his "cell of Isis-inspired terrorists".
US congressman Mike McCaul, Republican chairman of the House Homeland Security Committee, said the bomb was of a "level of sophistication" that might indicate its maker had foreign training.
He described it as "a classic explosive device used by terrorists", using the same substance as the one used in the deadly November 2015 attacks in Paris and the March 2016 attack in Brussels.
Mr McCaul said evidence so far suggests "we're not dealing with a lone wolf situation", adding: "There's a network - a cell of ISIS-inspired terrorists."
The investigation into the Manchester Arena atrocity has continued apace as security agencies swooped on the suicide bomber's suspected network.
Two men were arrested by police in Greater Manchester overnight on Thursday, bringing the number in UK custody to eight.
One of the men was detained following searches of an address in the Withington area of the city, while another was arrested in a part of Greater Manchester that was not disclosed.
On Wednesday, a series of raids were executed across Manchester, Wigan and Nuneaton in Warwickshire, while relatives of Abedi were detained in Libya.
In the early hours of Thursday morning, counter-terror police carried out a controlled explosion at a property in the Moss Side area of Manchester, although no arrests were reported by police.
Abedi's father, Ramadan Abedi, was arrested in Tripoli with his brother Hashim, who Libyan security forces said was "aware of all the details" of the attack.
Abedi's older brother Ismail, 23, was detained in south Manchester, on Tuesday.
Ramadan Abedi had earlier claimed Salman was innocent, saying: "We don't believe in killing innocents. This is not us."
Twenty-two people were killed, including seven children, and dozens seriously injured when Abedi detonated his bomb, packed with nuts and bolts, as fans left an Ariana Grande concert on Monday night.
With Britain on critical alert for further attacks:
The Government announced that a minute's silence will be held at 11am on Thursday
Mrs May will chair the fourth meeting of the Government's Cobra emergency committee since the attack before heading for the Nato summit in Brussels
A spokesman for Libyan authorities said one of Abedi's final acts was to ring his mother. The official also said his brother Hashim had told officials: "I know everything about my brother, what he was doing there in Manchester."