THE UK wide terror threat level in the wake of the Manchester attack has been reduced from critical to severe.

The threat level had been raised following the suicide bomb terror attack at the Manchester Arena on Monday which claimed 22 lives, including those of seven children, leaving scores injured.

Assistant Chief Constable Martin Evans of West Mercia Police said: "Prime Minister Theresa May has announced today (Saturday) that the UK threat level has been reduced to severe.

"We put additional local policing resources in place across the county for reassurance and we have taken the decision that this will continue throughout the bank holiday weekend.

"It has been heart warming to see how our officers and the community have continued to work together so positively following the tragic events at the beginning of the week.

"The additional armed officers you may have seen at iconic locations, transport hubs and events, following the national activation of Operation Temperer, will remain in place throughout the bank holiday weekend providing additional reassurance.

"This includes Lets Rock Shrewsbury today and the Ironbridge WW2 Weekend.

"The UK Threat Level had been at severe since August 2014 until this week when it was increased following the horrific attack at the Manchester arena.

"This means that an attack is highly likely. Therefore we continue to urge our communities to remain vigilant."

Police continue to unravel the bomb-making methods of the Manchester suicide attacker and close in on suspected co-conspirators.

Detectives were said to have a "greater understanding" of the way Salman Abedi built the device which detonated in a crowd of concert-goers on Monday.

A wave of arrests and raids are believed to have closed the net on the terror ring behind the attack, but counter-terror chief Mark Rowley warned "more arrests and more searches" could follow.

Prime Minister Theresa May announced on Saturday that troops will gradually be withdrawn from the streets from Monday onwards, having been drafted in to bolster police numbers.

The de-escalation in the country's threat level from its highest point suggests confidence that the operations conducted in the last week have stifled any imminent threats.

Currently 11 people remain in police custody after a raid on an address in the Cheetham Hill area of Manchester saw a 20-year-old and a 22-year-old detained on suspicion of terror offences.

It came amid searches at a separate property in Cheetham Hill and an address in the Longsight area in south Manchester, while a road in Moss Side was evacuated by officers searching a home there.

It is the worst terrorist outrage to hit Britain since the July 7 attacks in 2005.

A huge bank holiday weekend security operation is under way as tens of thousands of people attend major spectacles including the FA Cup Final at Wembley and the Premiership Rugby Final at Twickenham.

Arrangements have been reviewed at more than 1,300 events, while the pool of armed officers available to be deployed around the country has been boosted by 1,100 after military personnel were drafted in to cover guard posts at key sites.

To report any suspicious behaviour or activity on 0800 789 321. In an emergency you should always call 999.