MANCHESTER, UK--The UK terror threat level has been raised to its highest level of "critical", meaning further attacks may be imminent, Theresa May has said.

The move came after investigators were unable to rule out whether Manchester bombing suspect Salman Abedi acted alone, the prime minister said.

Military personnel will now be deployed to protect key sites.

Twenty-two people were killed and 59 injured when a suicide bomber attacked Manchester Arena on Monday evening, at the end of a concert by singer Ariana Grande.

The prime minister also confirmed the government had triggered "Operation Temperer", a long-standing emergency plan to put soldiers into key public locations to support armed police in protecting the public.

Third time

Military personnel may also be seen at other events over the coming weeks, such as concerts, Mrs May said, and would work under the command of police officers.

The prime minister said she did not want the public to feel "unduly alarmed" but said it was a "proportionate and sensible response".

She said the government would take "every measure available to us" to help the police protect the public.

"The spirit of Manchester and the spirit of Britain is far mightier than the sick plots of depraved terrorists.

"That is why the terrorists will never win and we will prevail," she said.

The highest level, which is decided by the Joint Terrorism Analysis Centre, a group of experts from the police, government departments and agencies, has only been reached twice before.

The first occasion was in 2006 during a major operation to stop a plot to blow up transatlantic airliners with liquid bombs.

The following year, security chiefs raised it once more as they hunted for the men who had tried to bomb a London nightclub, before going on to attack Glasgow Airport.

Former Salford University student Salman Abedi, understood to be a 22-year-old born in Manchester to parents of Libyan descent, is thought to have blown himself up in the arena's foyer shortly after 22:30 BST on Monday, as fans were beginning to leave a concert by US singer Ariana Grande.

Three of his victims have been named, Saffie Rose Roussos, eight, Georgina Callander, thought to be 18, and John Atkinson, 28.

Greater Manchester Police has said the priority was to establish whether Abedi had worked alone or not.

A man set off a homemade bomb in the foyer Monday night in what was described as a terrorist attack.

Armed police have arrested a 23-year-old man in Chorlton, south Manchester, in connection with the attack. The actual bomber is believed among the dead.

Sixty ambulances went to Manchester Arena after the attack and took the wounded to eight hospitals around the city. Among them are 12 children under the age of 16.

Several people are still missing.

In a statement in Downing Street on Tuesday, Prime Minister Theresa May said the bombing had been a "callous terrorist attack" that targeted "defenseless young people".

So-called Islamic State has said, via IS channels on the messaging app Telegram, it was behind the Manchester attack, but this has not been verified.

Greater Manchester Police Chief Constable Ian Hopkins said the "fast-moving investigation" was now working to establish whether the attacker "was acting alone or as part of a network".

Officers have carried out raids at two properties, one in Whalley Range and one in Fallowfield, where a controlled explosion was carried out.

In its latest statement the force said the area around the arena remained cordoned off but said it wanted to "remind people that Manchester will not be defeated - the city is open for business." (Source: BBC)

Story Date: May 24, 2017