 -- The mayor of Manchester lashed out after crime scene photos from the bombing there that left 22 dead were leaked to the media -- calling doing so "wrong and disrespectful."

"I felt sick to the pit of my stomach," Manchester Mayor Andy Burnham told ABC News, describing his reaction to seeing crime scene photos published on The New York Times website. The photos were subsequently published elsewhere, including ABC News.

Burnham, a former rising star in the Tony Blair Labour Party who was elected mayor this month, said he thought the forensic images were especially distressing to victims' families. Burnham said he has been to the crime scene, which he called a "harrowing experience," but he said the families of the victims have not had that chance yet.

"To see pictures of it not even in the media here," he told ABC News. "It was a pretty, pretty tough thing to see."

Burnham said he thinks the leak is "wrong, it is arrogant, and it is disrespectful to the people of Greater Manchester and particular to the families of those injured during this, our darkest hour."

The source of the leak was not clear, but President Donald Trump called for an investigation. U.K. Prime Minister Theresa May said she would talk to Trump at the NATO summit about safeguarding shared intelligence.

"On the issue of the intelligence sharing with the United States of America, we have a special relationship with the USA. It is our deepest defense and security partnership that we have," she said in Brussels. "Of course that partnership is built on trust and part of that trust is knowing that intelligence can be shared confidently and I will be making clear to President Trump today that intelligence shared between law enforcement agencies must remain secure.”

The New York Times said in a statement that the images and information it published "were neither graphic nor disrespectful of victims, and consistent with the common line of reporting on weapons used in horrific crimes, as The Times and other media outlets have done following terrorist acts around the world, from Boston to Paris to Baghdad, and many places in between. Our mission is to cover news and inform our readers. We have strict guidelines on how and in what ways we cover sensitive stories. Our coverage of Monday’s horrific attack has been both comprehensive and responsible."

Twenty-two people were killed in Monday night's suicide bombing, including a female police officer and an 8-year-old girl.

Salman Abedi, 22, the suspected suicide bomber, died at the scene of the attack.

Burnham said that after the name of the suspected bomber first leaked to the U.S. media, he personally called the acting U.S. ambassador to Britain and said he was assured that the leaks would stop.

"I've raised my concerns all week about the leaking of information to U.S. media outlets," Burnham said, "I communicated it personally ... to the acting ambassador here who understood my concerns and said it would stop."

But "it hadn't stopped," he added, calling that "unacceptable."

Burnham said the lead of the investigation should have control over the release of information so it is not compromised.

"I don't want a diplomatic row with my friends in the United States of America. We're longstanding allies," he said. "We want to work together on the same basis of trust that we've always worked."

The mayor's message to the U.S. government is "this must stop immediately," calling the leaks "morally wrong."

Burnham said a statement that he believes the U.S. government should issue an apology.

"I'm not blaming the American public," he said. "However I do look to the president and his senior team to make it clear that this is unacceptable."

Shortly after Burnham's interview with ABC News, President Trump released a statement saying, "The alleged leaks coming out of government agencies are deeply troubling. These leaks have been going on for a long time and my Administration will get to the bottom of this. The leaks of sensitive information pose a grave threat to our national security. I am asking the Department of Justice and other relevant agencies to launch a complete review of this matter, and if appropriate, the culprit should be prosecuted to the fullest extent of the law. There is no relationship we cherish more than the Special Relationship between the United States and the United Kingdom."

Attorney General Jeff Sessions added in a statement, "We have already initiated appropriate steps to address these rampant leaks that undermine our national security."

"These leaks cannot be tolerated and we will make every effort to put an end to it," Sessions said.

British Prime Minister Theresa May said Thursday that progress was being made in the investigation into Monday's attack, but reiterated that the national threat level is still at critical -- meaning that an attack could still be imminent.

Eight people are in custody in Britain in connection with the investigation, including one of the suspect's brothers, according to a security official. Another one of the suspect's brothers and the suspect's father have been detained in Libya.

Burnham said the investigation is targeting a terror "network" in Manchester and added that those arrested in Britain were previously known to authorities.

Greater Manchester Police chief constable Ian Hopkins said today, "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, as you would expect, therefore there will be some disruption," he said. "However, it is important that we continue with these searches."