Man arrested as anti-terror police carry out new raids in Manchester bomb probe

Eight men are in custody in connection with Monday's atrocity, with police and security agencies working at pace amid fears of further attacks.

Meanwhile, with the British General Election campaign due to resume on Friday, Jeremy Corbyn has signalled his intention to bring the issue of terrorism into the political arena.

The Labour leader is expected to make a veiled attack on the Conservatives for underfunding the police service at a time of heightened threat, while linking Britain's overseas military campaigns with terrorism at home.

On Thursday, UK police resumed "working closely" with US authorities on the probe after a tense showdown between the allies over leaked intelligence.

With Britain on critical alert, a huge operation is under way to dismantle a suspected "network" linked to suicide bomber Salman Abedi, who killed 22 people, seven of them under 18.

Mark Rowley, the UK's most senior counter-terrorism officer, confirmed British chiefs had "received fresh assurances" from their overseas counterparts that they could be trusted with confidential material.

Home Secretary Amber Rudd said she expected the "critical" assessment of the terror threat - suggesting a fresh attack may be imminent - to remain in place in the coming days.

Ms Rudd told BBC1's Question Time: "During this period of 'critical', which we hope will only last for a few days - it could be longer, it will depend on the operation - we've pulled out additional support from the Army so we can go about our normal life."

The developments followed a fraught day in which Greater Manchester Police severed intelligence-sharing ties with the US due to evidence being repeatedly passed to journalists without permission.

"While we do not usually comment on information-sharing arrangements with international law enforcement organisations, we want to emphasise that, having received fresh assurances, we are now working closely with our key partners around the world including all those in the Five Eyes intelligence alliance," Mr Rowley said.

Abedi, who was known to security services for his radical views, was said to have been in close contact with family members moments before slaughtering concert-goers on Monday.

A relative of the 22-year-old said he had felt increasing frustration at his treatment in the UK, heightened after a friend was fatally knifed in what he perceived to be a religious hate crime.

She added that the British-born bomber began referring to others in the country as "infidels" who were "unjust to Arabs".

Libyan authorities, who are questioning Abedi's parents and siblings, claimed he made a final phone call to his mother on the eve of the attack, in which he said: "Forgive me."

Music fans were targeted at an Ariana Grande concert at Manchester Arena in the worst terrorist attack on British soil since the July 7 bombing in London in 2005.