British police say they have arrested a sixth person as they continue investigating a "network" over the attack at a pop concert in Manchester that killed 22 people, some of them children.
Police said the woman was arrested on May 24 following searches in Blackley, an area north of the city center.
"I think it's very clear that this is a network that we are investigating," Ian Hopkins, head of Greater Manchester Police, said on May 24, adding that police were carrying out "extensive searches" across Manchester.
British Interior Minister Amber Rudd earlier said the May 22 attack was "more sophisticated than some of the attacks we've seen before, and it seems likely -- possible -- that [the bomber] wasn't doing this on his own."
Rudd told BBC radio it appeared that the bomber, identified by the police as British-born Salman Abedi, 22, had recently returned from Libya. Abedi was of Libyan descent.
The suspected bomber's father, Ramadan, and younger brother, Hashem, have been arrested in the Libyan capital, Tripoli, a relative and a spokesman for a local counterterrorism force said.
Hashem was arrested on suspicion of links with the IS group, according to Reuters news agency.
British police arrested the older brother, Ismael, on May 23.
They said the fifth suspect they arrested earlier on May 24 was carrying a package, which they were still assessing.
The extremist group Islamic State (IS) has claimed responsibility for the bombing, saying it targeted "crusaders" and was carried out by "one of the caliphate's soldiers" -- wording that leaves the extent of the perpetrator's alleged ties with the group unclear.
The British-Libyan community in Manchester released a statement condemning the bombing as "an attack on all of us."
Rudd said she was "not surprised at all" that IS claimed responsibility for the attack, but that there was no information yet to confirm the extremist organization's active direction.
Soldiers In The Streets
French Interior Minister Gerard Collomb said that Abedi was believed to have traveled to Syria and had "proven" links with the IS group.
Meanwhile, The New York Times newspaper published photos which it says were gathered by British authorities at the scene of the attack, including the remnants of a backpack, shrapnel including nuts and screws, and a device identified as a "possible detonator."
Military personnel were being deployed to protect Britain's key sites after the national terror-threat level was raised late on May 23 to "critical," meaning another attack may be imminent.
Rudd said that up to 3,800 military personnel would be deployed on Britain's streets following the bombing, which was carried out as concertgoers -- many of them teenagers and younger children -- were leaving a show by American pop singer Ariana Grande.
London police said on May 24 they would be calling in the army to help guard key landmarks, including Buckingham Palace, the Houses of Parliament, and foreign embassies.
The last time British troops were deployed on the streets was after an airliner plot in 2007.
The attack was the deadliest in Britain since July 7, 2005, when four suicide bombers attacked London's transport system during rush hour, killing 52 people.
Children Among Dead, Critically Wounded
The attack in Manchester has drawn particular international condemnation because children were targeted.
The victims included 8-year-old Saffie Rose Roussos; Nell Jones, 14; Sorrell Leczkowski, also 14; and Olivia Campbell, 15.
Police said an off-duty policewoman was among the victims.
A Polish couple were also confirmed among the dead.
A British health official said on May 24 that about 20 people remained in critical condition.
"We are now treating 64 individuals.... Of those, approximately 20 are receiving critical care. That means very urgent care," Jon Rouse, chief officer for health and social care services in the greater Manchester area, told Sky News.
"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. These are highly traumatic injuries," he said.
Authorities had earlier said that 59 people were taken to hospitals, many with life-threatening injuries, and that 12 of them were under 16 years old.
Late on May 23, thousands of people gathered at Albert Square in central Manchester to mourn the dead, a display of defiance and solidarity in the face of the attack and the persistent threat.
"The spirit of Manchester and the spirit of Britain is far mightier than the sick plots of depraved terrorists," May said in London on May 23. "That is why the terrorists will never win, and we will prevail."