British Prime Minister Theresa May has said she will "make clear" to U.S. President Donald Trump that intelligence shared between the two countries must remain secure, Britain's Press Association news agency has reported.
The reported remark on May 25 followed reports that British police are concerned that U.S. leaks of intelligence on the May 22 attack at a pop concert in Manchester could hamper efforts to find a possible bomb maker who may still be at large.
May held a meeting of the government's emergency security cabinet, known as Cobra -- the fourth such meeting since the attack.
Officials believe suspected suicide bomber Salman Abedi, 22, was part of a network, and are hunting for accomplices who might have helped him build the bomb that killed 22 people -- some of them children -- and injured about 60.
Abedi's name was leaked to U.S. media just hours after the attack, prompting Home Secretary Amber Rudd to say she was "irritated" by the disclosure and warn Washington "it should not happen again."
However, pictures of the debris from the blast appearing to show bloodstained bomb fragments and the backpack used to transport the device that appeared in The New York Times, sparking an angry reaction from British officials.
Without citing a source, the BBC reported that police investigating the attack have stopped sharing information with the United States following the leaks.
Separately, the Associated Press quoted an unnamed British official as saying that the Manchester police will stop sharing bombing-investigation information with U.S. officials amid anger over the leaks.
There was no official confirmation of the reports from British authorities.
The Islamic State (IS) extremist group claimed responsibility for the attack, which was the deadliest in Britain since 56 people were killed in an attack on the London transport system in 2005.
Meanwhile, Manchester city police chief Ian Hopkins told reporters on May 25 that the authorities have made significant arrests and have uncovered important items during the investigation.
Greater Manchester police are holding eight people in custody, having released a woman without charge on May 25, Hopkins said.
"I want to reassure people that the arrests that we have made are significant, and initial searches of premises have revealed items that we believe are very important to the investigation.
"These searches will take several days to complete," he said.
Referring to the leaking of evidence from the investigation that appeared in The New York Times, Hopkins said it was "absolutely understandable" that this caused "much distress" to families of victims already suffering with their loss.
Queen Elizabeth visited victims at a children's hospital in Manchester, and a minute of silence was held in Britain on May 25 at 11 a.m. (1000 GMT/UTC) to remember the victims.
The minute of silence was held amid reports that a bomb-disposal team was sent to a college in the Manchester suburbs after police responded to a call there. Police later indicated it was a false alarm, saying a suspicious package had been "deemed safe."