A group of UK police chiefs blasted intelligence officials in the US on Wednesday for leaking photographs of evidence relating to the suicide bombing in Manchester earlier this week.

In decrying the leaks, the National Police Chiefs’ Council joined other UK government officials who have expressed frustration with their American security allies since the attack, which killed 22 people and injured more than 50 others Monday.

On Wednesday, The New York Times published pictures of remnants of the attacker’s homemade bomb, including a shredded backpack, a 12-volt battery, and nuts and screws used as shrapnel.

In a statement, a spokesperson representing the British police group’s counterterrorism committee said the leaks “undermine our investigations and the confidence of victims.”