The row came as police pressed a fast-paced investigation into Monday’s bombing, which killed 22 people at a music venue packed with children and raised fears a further attack could be imminent. Troops have been deployed to guard key points and eight people have been arrested.

Authorities have said the 22-year-old bomber, British-born Salman Abedi, was part of a network and had recently returned from Libya, where his parents were born.

Police chiefs have made clear they are furious about the publication of confidential material in U.S. media, including bomb site photographs in the New York Times, saying such leaks undermined relationships with trusted security allies.

“This damage is even greater when it involves unauthorised disclosure of potential evidence in the middle of a major counter-terrorism investigation,” a National Counter Terrorism Policing spokesman said in a statement.

British Prime Minister Theresa May will raise the issue with U.S. President Donald Trump when she meets him at a NATO summit in Brussels later on Thursday, a government source told Reuters.

The pictures published by the New York Times included remains of the bomb and of the rucksack carried by the suicide bomber, and showed blood stains amid the wreckage.

“I think it’s pretty disgusting,” said Scott Lightfoot, a Manchester resident, speaking outside a train station in the city. He criticised media for publishing such material.

“Who’s leaking it? Where’s it coming from? This is British intelligence at the end of the day, people shouldn’t be finding out about this.”

“Bomb-Making Workshop”

The Financial Times reported that such images are available across a restricted-access encrypted special international database used by government ordnance and explosives experts in about 20 countries allied with Britain. It said the database was built around a longstanding U.S.-British system.

The BBC said Manchester Police hoped to resume normal intelligence relationships soon but was currently furious.

The bombing, which took place at the Manchester Arena indoor venue just after the end of a concert by U.S. pop singer Ariana Grande, was the deadliest in Britain since July 2005, when 52 people were killed in attacks on London’s transport network.

The Manchester attack has caused revulsion across the world because it targeted children and teenagers, who make up the bulk of Grande’s fan base. The victims ranged from an eight-year-old schoolgirl to parents who had come to pick up their children.

U.S. channel ABC News reported that police had found a kind of bomb-making workshop in Abedi’s home and he had apparently stockpiled enough chemicals to make additional bombs.

British news website The Independent also reported bomb-making materials which could be primed for imminent attacks had been found in the raids following the Manchester bombing. The report said one suspect device was blown up in a controlled explosion.

Britain views the United States as its closest ally, and the two countries also share intelligence as part of the “Five Eyes” network which also includes Australia, Canada and New Zealand.

After Trump defended his decision to discuss intelligence with the Russians during a White House meeting, May said last week that Britain would continue to share intelligence with the United States.