UK Home Secretary Amber Rudd today slammed United States leaks on the investigation into the deadly Manchester terror attack as "irritating" and said she had made it clear to Washington that it "should not happen again".
The new arrests came as the injured toll doubled from 59 to 119.
Eight men have been arrested and remain in custody in connection to the bombing and a woman arrested in a raid in Blackley, Wednesday has since been released without charge, police said.
A string of details about Monday's attack at an Ariana Grande concert at Manchester Arena that killed 22 people and injured over 100 others have emerged from USA law enforcement sources before being released by British police or officials.
Some police say privately they believe security in the capital - 250 km (160 miles) to the south of Manchester - has been prioritised at the expense of other cities, where staff cuts have hit hard, career opportunities have been reduced and many officers fear for their jobs.
Manchester Police Chief Constable Ian Hopkins told reporters it was very clear they were investigating what he called "a network". Hopkins added that police have spoken with the immediate families of all the victims.
British Prime Minster Theresa May will meet US President Donald Trump at a North Atlantic Treaty Organisation summit in Brussels on Thursday, but officials said she would cut short the second leg of her trip to the G7 summit in Italy.
Prime Minister Theresa May said security officials had raised their assessment of the threat to Britain to "critical", indicating an attack was imminent. He has since returned to Libya.
Gerard Collomb said on BFM television Wednesday that British and French intelligence have information that British-born attacker Salman Abedi had been to Syria. "I was really shocked when I saw the news, I still don't believe it", he said in Tripoli.
The singer reportedly had just finished her last number at about 10:35 p.m. local time and the lights had come on when a loud explosion punctured the warm night.
The unnamed officer is from Cheshire Police and her husband is critically ill.
Abedi, who was born in Manchester in 1994 to Libyan parents, blew himself up on Monday night at the Manchester Arena indoor venue at the end of a concert by U.S. pop singer Ariana Grande attended by thousands of children and teenagers.
The singer has since flown back to the USA and officials have said there remains uncertainty over whether two of her other planned concerts at London s O2 Arena on Thursday and Friday would go ahead.
She was off duty at the time, and had been at the concert with her two children, who were also hurt in the blast. "The children are safe".
After the Home Office has carried out postmortems in the coming days, the victims will be officially named.
Images from today's (23 May 2017) vigil in Manchester's Albert Square. It said all the affected families have been contacted and trained officers are supporting them.
She also complained about USA officials leaking sensitive information about Abedi to the press, saying that could take "the element of surprise" away from Britain's security services and police.
President Trump, in Israel on Tuesday, called the Manchester attack the work of "evil losers."
It also published a diagram showing most of the fatalities occurred in a circle around the bomber, which it said indicated a powerful, high-velocity charge.
Up to 3,800 military personnel would be available to support police, Home Secretary Rudd said, amid warnings of another potential attack.
Britain also has a national election scheduled for June 8.