ARMED troops are to guard nuclear power plants in Scotland and other sensitive sites across the UK as the police said they were now investigating a "network" linked to the Manchester bomber.

More of the 22 murder victims have been named. Their number includes an off-duty female police officer. Meantime, fears grow for 14-year-old Eilidh MacLeod, from Barra, who, three days on, remains unaccounted for.

As many of the young victims of the terror attack continue to receive hospital treatment, it emerged how one, Freya Lewis, also 14, underwent 10 and a half hours of surgery to her wounds. It is thought her life was saved by a couple who gave her CPR. She is in a stable condition.

Today, a UKwide minute’s silence will be observed at 11am in remembrance of those killed and injured in Britain's worst terrorist atrocity since the 7/7 attacks in London 12 years ago.

After that, local General Election campaigning will restart with the full national campaign resuming on Friday. Labour leader Jeremy Corbyn insisted terrorism must not be allowed to “derail our democratic process”.

With the security level raised to “critical,” meaning an attack is expected imminently, almost 1,000 troops are being deployed to support the police in order to prevent another terror attack.

At Holyrood, Nicola Sturgeon explained how military personnel would secure 12 sites in Scotland under so-called Operation Temperer; nine Ministry of Defence establishments as well as three nuclear sites.

The First Minister stressed that “no specific threat to Scotland has been identified” and added that soldiers were not expected to be deployed on the streets of Scotland but this would be kept under review by Police Scotland.

South of the border, armed troops are being used to guard "key locations" such as Buckingham Palace, Downing Street, the Palace of Westminster and foreign embassies. This will free up armed police officers to carry out street patrols elsewhere.

Scotland Yard explained how extra armed officers would also provide support for an operation called Project Servator in which uniformed and undercover police attempt to spot people carrying out "hostile reconnaissance" and other criminal activity.

The enhanced security plan means soldiers could be deployed to support police at major events such as the FA Cup final at Wembley on Saturday or the Champions League final in Cardiff on June 3.

In Scotland, the police are completing a review of every upcoming public event, including the Lisbon Lions memorial in Glasgow on Thursday, the visit to Edinburgh on Friday of former US President Barack Obama, Saturday’s Scottish Cup Final and this weekend’s Edinburgh Marathon.

Just 48 hours after 22-year-old Salman Abedi killed 22 people and injured 59 others, many seriously, by detonating a suicide bomb at a pop concert in the Manchester Arena, police said their extensive investigations were moving at speed.

Ian Hopkins, Greater Manchester Police’s Chief Constable, asked if officers were now hunting for the bombmaker, said: “It's very clear that this is a network that we are investigating and…it continues at pace.” He added: “Activity[is] taking place across Greater Manchester as we speak."

During Wednesday three men were arrested after police executed warrants in the south of the city. Another was later arrested in Wigan, taking the total of people in custody to five. Armed officers also carried out a search at another address in Manchester city centre while a “huge bang” was heard during a police raid on flats in Blackley, north Manchester.

In the early hours at an address in Fallowfield, less than a mile from Abedi’s home, neighbours said a Libyan father, his wife and their two sons, aged in their late teens or early 20s, were taken away by armed police.

It emerged that Abedi had not only recently travelled to Libya, from where his parents hailed, but might have been trained in Syria by extremists from so-called Islamic State.

Gerard Collomb, France's Interior Minister, said both British and French intelligence services had information that Abedi had been in Syria.

He told French television: "We only know what the British investigators have told us. He was a British national of Libyan origin, he grew up in Great Britain. All of a sudden he travelled to Libya and then most likely to Syria, became radicalised and decided to commit this attack."

He insisted Abedi’s “links with Daesh[so-called Islamic State] are proven."

Amber Rudd, the Home Secretary, confirmed Abedi, whom the intelligence services knew "up to a point," had recently returned from a visit to Libya, where his parents are said to live, and noted how the nature of the attack suggested he might have had support.

"It was more sophisticated than some of the horrific events that we have seen in the past or in other parts of Europe so people are reasonably wondering whether he did this on his own," she explained.

The IS terror group has claimed responsibility for Monday’s barbaric attack, which involved a home-made device packed with nuts and bolts. It exploded in the venue's foyer as thousands of young people were leaving the Ariana Grande pop concert.

The New York Times released a series of images it claimed showed the components of the Manchester bomb, suggesting it was a sophisticated, powerful device.

The preliminary analysis of the bomb by British authorities is said to indicate it was a powerful explosive, which was carried in a “lightweight metal container concealed either within a black vest or a blue Karrimor backpack”. Abedi is thought to have “held a small detonator in his left hand”.

Today, Theresa May will attend a Nato summit in Brussels, where she will again condemn the Manchester bombing as “a callous and cowardly act”.

On Friday, the Prime Minister will attend the G7 summit in Sicily, where, Downing Street said, she would take the lead on the issue of counter-terrorism.

Mrs May had intended to stay in Italy until Saturday but No 10 confirmed that, due to the security situation in the UK, she would now be returning on Friday night.