(Bloomberg) —British police condemned U.S. officials’ leaking of intelligence relating to the Manchester terror attack, calling it a breach of trust that risks undermining their investigations as the probe into the bombing extended to Libya.

The strongly-worded rebuke came after the New York Times published photographs of the crime scene and after Home Secretary Amber Rudd openly criticized U.S. officials for sharing details with American media organizations before British security services were ready to do so. The Times story followed several U.S. news reports disclosing information British police and intelligence officials had chosen to withhold from the press.

“We greatly value the important relationships we have with our trusted intelligence, law enforcement and security partners around the world,” the National Counter Terrorism Policing office said in a statement on Wednesday evening. “When that trust is breached it undermines these relationships, and undermines our investigations and the confidence of victims, witnesses and their families. This damage is even greater when it involves unauthorized disclosure of potential evidence in the middle of a major counter terrorism investigation.”

Manchester police said on Wednesday they’re investigating a network they think orchestrated the bombing, and the suspected perpetrator’s father and brother were arrested in Tripoli. Seven arrests have so far been made in the U.K. in connection with the attack.

Prime Minister Theresa May will cut short her trip to the Group of Seven meeting in Sicily, returning Friday night to deal with the terror threat. She is expected to raise the issue of intelligence leaks with U.S. President Donald Trump, according to the Guardian newspaper, amid speculation that key allies could become reluctant to share vital security information with the world’s superpower.

‘Very Troubled’

Manchester’s mayor, Andy Burnham, told the BBC he had raised concerns about the leaks with the U.S. ambassador, while Labour lawmaker Yvette Cooper said she was “very troubled” by those occurring in the middle of an investigation where public safety may be at risk. Before further details were published by the New York Times, Rudd had said she had been “very clear with our friends that that should not happen again.”

The victims of the attack were still being identified on Wednesday, and pictures of British troops deployed in the central government district in Westminster, armed with assault rifles, dominated the news. The deployment, designed to free up police officers to pursue the terrorists behind the attack, is the largest on the British mainland in decades.

Police now say that the suspected bomber, 22-year-old Salman Abedi, who died in the attack, was part of a network. Manchester police arrested a man reported to be Abedi’s brother. Another brother and the suspect’s father were arrested in Libya, witnesses and security forces said. A woman was arrested following an armed raid in Manchester on Wednesday evening.

Unified Front

Britain’s political parties meanwhile agreed to resume campaigning on Friday after a three-day break, as authorities warned that another attack is imminent. With two weeks to go until the June 8 election, it’s likely to be a different style of campaign after the worst terrorist attack on British soil in more than a decade.

On Monday morning, May had been on the defensive, denying that she’d reversed one of her flagship policies on care for the elderly. The murder that evening of 22 people — including children — at a pop concert moved her into the role of a leader at a time of national crisis, and politicians on all sides have been careful to show a united front.

May’s Conservatives will resume local activities such as canvassing households on Thursday and full national campaigning on Friday. The opposition Labour Party will pursue a similar timetable, its leader Jeremy Corbyn said. The U.K. Independence Party, whose manifesto launch was delayed amid the suspension, will unveil its program on Thursday.

“Resuming democratic debate and campaigning is an essential mark of the country’s determination to defend our democracy and the unity that the terrorists have sought to attack,” Corbyn said in a statement. “It will not prevent us going about our daily lives or derail our democratic process.”

Soldiers may also be used to bolster security at crowded events. Major sporting events including soccer’s FA Cup final at the national stadium in Wembley in northwest London are scheduled for this weekend, and police have said they are reviewing security.

So far a total of 984 soldiers had been drafted into helping police in London and elsewhere, and as many as 3,800 could be used, according to Rudd. Warner Bros. canceled their planned U.K. premier of the film “Wonder Woman,” scheduled for May 31 in London, due to the terror threat, according to newspaper reports.

Such a widespread deployment is highly unusual in mainland Britain. Outside of wartime and the London 2012 Olympics, when troops provided additional security, the closest example may be the 1926 General Strike.