BRUSSELS — UK and European intelligence officials are expressing concern over the fact that much of the information that emerged in the wake of the Manchester bombing has been sourced back to US officials.

The information first came in the hours after the attack — including a US official saying that the leading theory was that the attack was carried out by a suicide bomber — and culminated in a report by CBS News and the Associated Press that cited US officials claiming to identify the suspect who is believed to have blown himself up during an Ariana Grande concert at Manchester Arena, killing at least 22 people. The Manchester police would later confirm only the name of the suspect — 22-year-old Salman Abedi — to the press, and the arrest of another 23-year-old suspected in connection to the attack.

One Belgian counterterrorism official who spoke with BuzzFeed News between a series of meetings about the Manchester attack confirmed the discomfort felt in European intelligence circles.

"It happens sometimes when a larger partner like America assists on an investigation like this one," said the official, who asked not to be identified because he lacks permission to speak with the press. "You know you are trading the additional resources they bring for a chance of increased leaks. In this case, I suspect the Brits are livid — I know we would be — to have a suspect ID'd before they're ready, and obviously the recent performance of the Trump administration on leaking sensitive information can't be far from anyone's mind if they examine [the situation]."

Even US officials were frustrated by the leak. Some called the US decision to release information about an ally’s investigation before even that nation had released it “unprofessional.” Others said that if it were the US investigating an attack, US officials could expect the UK to not release information about the case.

“The least we can do is give them that same respect,” one US official told BuzzFeed News.

Although it is unlikely the incident will hurt the sharing and coordination of information between the closely linked UK and US intelligence services, one US-based expert questioned why US officials would leak in the first place.

“Why get in the way of what they are trying to do?” asked Thomas Joscelyn, senior fellow at the Foundation for Defense of Democracies. “Follow their lead unless there is some good reason not to. The UK made a conscious decision to not release the suspect’s name. They have a good reason for doing that and US officials should probably wait for the UK to come out with specific details.”

The leaks come at a time when trust between the US intelligence services and others has been strained by the behavior of President Donald Trump, who shared classified details with Russian officials during an Oval Office meeting earlier this month.

Shashank Joshi, a research fellow at the security think tank Royal United Services Institute, told BuzzFeed News British authorities may need to address the apparent leaks by US intelligence sources of information obtained from the UK.

"UK officials will have other priorities at the moment, but when the dust settles they will be concerned by the way in which British information was leaked by US officials, sometimes hours ahead of its confirmation," Joshi said. "Police and intelligence officials would have had their reasons to hold back on key details, such as casualty figures and the method of attack, but this was impossible in a more international, free-wheeling media environment."

Joshi added it was “dismaying” that US media had published — citing US intelligence sources — a suspect’s name at an early phase of investigation, but said it was not unprecedented for this to happen, citing examples including the naming of Mohammed Emwazi as the ISIS fighter known as “Jihadi John.”

Joshi said the day’s disclosures from US intelligence and military were “beyond the usual,” especially “given that most reputable US outlets consult with authorities as to whether publication will have damaging consequences.”