The brother of Salman Abedi, the suspect accused of carrying out a bombing in Manchester, England, that killed 22 people, allegedly said he knew his brother was going to carry out an attack, but did not know where or when, according to a spokesman for Libya's counter terror forces.
Nine people are now being held by police in connection with the bombing after an arrest in Rusholme, Greater Manchester on Friday.
"We are furious. This is completely unacceptable", a government ministry source said of the images "leaked from inside the United States system".
British authorities did not say the investigation had in fact been compromised by the leaks.
"Manchester is a busy place and this weekend we have the Manchester Games, the Great Manchester Run, the Courteeners concert and the start of Ramadan", Greater Manchester Police Chief Constable Ian Hopkins said.
Northern Railway says train services "that would normally run into Manchester Victoria are unable to do so", meaning "significant disruption" for trains in and around Manchester.More news: Wenger Coach in the dark as Arsenal verdict looms
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Prime Minister Theresa May is expected to raise the U.K.'s concerns with U.S. President Donald Trump during a North Atlantic Treaty Organisation summit in Brussels on Thursday.
With investigators pushing ahead with the probe into the attack, British authorities were left "furious" by repeated leaks of material shared with their USA counterparts that they said undermined the investigation.
As the nation mourned, Queen Elizabeth II visited children injured in the attack at a hospital in the northwestern English city.
A national minute's silence was to be observed at 11:00am for those killed and the dozens seriously wounded. Former U.S. President Barack Obama, meeting German Chancellor Angela Merkel at an event in Berlin, said the pair were "heartbroken", while Trump told fellow North Atlantic Treaty Organisation leaders the attack was "savage" and "barbaric".
A British official confirmed Abedi had been on the intelligence radar before the massacre. May said at the time Britain would continue to share information with Washington.
The images showed shreds of a blue Karrimor backpack, metal screws and nuts, the remains of a strong battery, and the apparent hand-held detonator with wires coming from it. He criticised media for publishing such material. "This is British intelligence at the end of the day, people shouldn't be finding out about this".
In a statement, the New York Times defended its decision to publish the images, saying they were "neither graphic nor disrespectful of victims". "Our coverage of Monday's horrific attack has been both comprehensive and responsible", the newspaper said.