Two more men have been arrested in Greater Manchester in connection with the concert bomb attack, bringing the number in UK custody to eight.
The investigation continues as security agencies swooped on the suspected "network" of Salman Abedi, the suicide bomber.
Twenty-two people have been killed and 116 injured when a device was detonated near an exit at the Manchester Arena.
According to the French interior minister Gerard Collomb, Abedi is believed to have travelled to Syria and had "proven" links with the Islamic State (IS) terror group.
Abedi's father, Ramadan Abedi, was also arrested in Tripoli with his brother Hashim, who Libyan security forces said was "aware of all the details" of the attack.
Meanwhile a statement claiming to be from IS says it carried out the attack.
The bomber blew himself up in the arena's foyer as fans were beginning to leave the concert by US singer Ariana Grande.
Seventeen out of 22 victims have now been publicly identified, including an 8-year-old girl and a police officer off-duty.
Twelve children under the age of 16 were among the 59 casualties taken to hospital.
A 22-year-old fan, Majid Khan, described what happened:
"A huge bomb-like bang went off that hugely panicked everyone and we were all trying to flee the arena"
Messages of sympathy and solidarity have been sent to the UK from across the world.
The Queen has expressed her "deepest sympathy" to all those affected.
Flags in many places have been flying at half-mast and books of condolence have also been opened at council offices and online.
Meanwhile, some of the major political parties will resume their General Election campaigning on Friday.
More to follow.
Cover picture courtesy of Jamie Grierson/Twitter.