British police arrested seven people by Wednesday evening in relation to the terrorist attack on a Manchester concert, confirming that alleged suicide bomber Salman Abedi was not acting alone. The arrests came as UK authorities reacted with anger to US authorities leaking key details of the attack.

According to a report in the German "Focus" magazine, the suspect flew to Manchester from Dusseldorf airport just days before he launched his attack at the concert arena. He is also believed to have been in Germany before, having flown from Frankfurt airport to Britain in 2015.

British intelligence were reported to be working with German authorities to find out who the suspect met and where he went.

Salman's older brother Ismail was among the six men and one woman who were arrested in the UK following the deaths of 22 people in a bombing on an Ariana Grande concert on Monday.

"It's very clear that this is a network that we are investigating," Greater Manchester Chief Constable Ian Hopkins told reporters.

"This evening we have been carrying out searches at an address in Nuneaton, Warwickshire, and arrested a man," the Greater Manchester Police force said in a statement. It was the first British arrest outside the Manchester region.

One of the suspects had carried a suspcious package through Manchester city center. Explosives were found at one site, the "Independent" reported, citing security service sources.

Three family members arrested

Meanwhile Libyan police arrested Salman Abedi's younger brother Hashim and father Ramadan this week. Hashim told Libyan police that both he and Salman were members of the so-called "Islamic State."

"The brother was aware of all the details of the terrorist attack," Libyan police said in a statement.

The father denied his son had links to Monday's bombing, telling The Associated Press: "We don't believe in killing innocents. This is not us."

"Salman doesn't belong to any organization," he told Reuters. "The family is a bit confused because Salman doesn't have this ideology, he doesn't hold these beliefs.

"I spoke to him about five days ago ... there was nothing wrong, everything was normal." He did not say where his son was at the time.

"I didn't expect that to happen, never," Abedi said, adding that he thought there were "hidden hands" behind the attack.

Police have identified 22-year-old Salman Abedi as the attacker who blew himself up at the Manchester Arena at the end of a concert. The attack left 22 people dead and more than 60 others wounded.

UK furious at leaks

Hours after British authorities reprimanded US officials for leaking details of the case, the "New York Times" published leaked images of the crime scene. 

British police chiefs said the leaks were undermining their efforts, while UK Interior Minister Amber Rudd earlier scolded US officials for leaking details.

"The British police have been very clear that they want to control the flow of information in order to protect operational integrity, the element of surprise, so it is irritating if it gets released from other sources, and I have been very clear with our friends that should not happen again," she said.

A government source told Agence France Presse, "We are furious. This is completely unacceptable. These images leaked from inside the US system will be distressing for victims, their families and the wider public."

"The issue is being raised at every relevant level by the British authorities with their US counterparts."

Prime Minister Theresa May will raise the issue at an upcoming G20 meeting, "The Guardian" reported.

Analysis of the "New York Times" images revealed that the bomb was likely a sophisticated construction inside a backpack with multiple levels of reduncancy, indicative of outside help.

It also published a schematic of the crime scene showing bodies circling the suicide bomber, whose torso was reportedly thrown outside of the ring towards the entrance of the arena doors.
Read more: Will Manchester change after the attack?

Threat level critical

With Abedi suspected of having had accomplices, the government late on Tuesday raised the official terror threat level to "critical," meaning that an attack was expected imminently. It marked the highest threat level in the UK in more than a decade.

French Interior Minister Gerard Collomb told local broadcaster BFM that the 22-year-old is thought to have also travelled to Syria, adding that he had proven links to the so-called "Islamic State" jihadist group.

Attacker's Middle East links

Amber Rudd said that Abedi had recently returned to the UK from Libya, although she declined to give further details concerning his trip. 

The minister said that as many as 3,800 troops could be deployed to patrol streets across the UK and guard vital locations, such as Buckingham Palace and the prime minister's residence at Downing Street. Just under 1,000 soldiers have already been deployed, initially in London, then elsewhere.

According to officials, this would free up police officers to carry out patrols and investigatory work amid fears of an imminent second attack.

The Houses of Parliament have been closed for visits. The defense ministry said the changing of the guard ceremony at Buckingham Palace has been cancelled so that police officers can be redeployed elsewhere.

Meanwhile, Prime Minister Theresa May on Wednesday morning chaired a meeting with her emergency security cabinet, known as Cobra, to collect intelligence reports on the attacker. 

Read more: Madrid to Manchester: A chronology of terror in Europe

Casualty updates

News concerning the victims of the attack continued to trickle through on Wednesday. An eight-year-old, two teenage girls and a 28-year-old man were also identified as among those killed in Monday's attack.

Hopkins confirmed that a serving police officer had also died.

Meanwhile, Poland's foreign minister announced that the death toll included a Polish couple, who were collecting their daughters from the venue.

Manchester health officials announced Wednesday that 20 people remained in "critical care" after suffering from "horrific injuries."

"There is damage to major organs, major injuries in terms of limbs and some of these individuals are going to need very long-term care and support," Jon Rouse, chief officer for health and social care services in the Greater Manchester area, told the British broadcaster Sky News. "These are highly traumatic injuries." Sixty-four people remain hospitalized, Rouse added.

Read more: Manchester resilient in the face of terrorism

aw, dm, mm/jm (Reuters, AP, AFP, dpa)