British police have released a photograph of Salman Abedi on the night he killed 22 people in a suicide bomb attack in Manchester and said they believed an apartment in the city centre was where he put together his device.

"We know one of the last places Abedi went was the city centre flat and from there he left to make his way to the Manchester Arena," Greater Manchester Police Chief Constable Ian Hopkins and Neil Basu, Senior National Coordinator UK Counter Terrorism Policing, said in a joint statement.

"The flat is highly relevant as a location which we believe may be the final assembly place for the device."

Mr Hopkins and Mr Basu said they had gathered significant information about Mr Abed, a 22-year-old Briton born to Libyan parents.

They said they had gathered details on how his bomb was built, who his associates were, his finances, the places he had been and the wider conspiracy.

However, police still need information the public might have about his movements from 18 May when he returned to Britain.

They said the investigation was not slowing, with some 1,000 officers involved, and the priority was to determine if more people were involved in planning the attack.

Earlier, British Prime Minister Theresa May said that the terror threat level in the UK has been reduced from "critical" to "severe".

The level was raised to "critical" - meaning another attack was thought to be imminent  - after Monday's attack.

It has now been downgraded to "severe", which means an attack is considered highly likely.

As a result, soldiers who have been assisting police, will be withdrawn from Britain's streets from midnight on Monday.

It follows two further arrests by British police as they stepped up their efforts to capture a suspected network behind the Manchester attack.

Detectives are now questioning 11 men over the attack by Abedi.

Some hours later, police cordoned off a large area in the Moss Side area of south Manchester and houses were evacuated with a bomb disposal unit sent to the scene.

"As part of an ongoing search at a property in Moss Side an evacuation is currently being carried in the area," police said in a statement.

While Britain's most senior counter-terrorism officer said police were confident that they had made "immense" progress and had apprehended a "large part of the network", extra armed officers will be on duty across the country with security stepped up at some 1,300 events over the long holiday weekend.

There are a number of high-profile events over the weekend including soccer cup finals in London and Glasgow, and the Great Manchester Run.

While police and politicians have praised communities in Manchester for their reaction to the bombing, Greater Manchester Police Chief Constable said there had been a rise in reported hate crimes, from an average of 28 to 56 incidents on Wednesday.

"We can't directly link these to the events of Monday night and are continuing to monitor the situation," he said.

Defence Minister satisfied with security in Ireland

Meanwhile, the Minister for Defence Paul Kehoe has said that he is satisfied that Ireland has the capacity to deal with an attack like the Manchester attack. 

Speaking at the naming ceremony of the recently refurbished Army Equitation School Arena in McKee Barracks in Dublin today, Minister Kehoe said that both he and the Taoiseach were reassured by the Garda Commissioner and the Chief Of Staff of the Defence Forces at a Government meeting last Thursday that Ireland has the capacity to deal with any such attack.

"We have highly trained and well equipped members of the Garda Síochána and the Defence Forces to deal with any eventuality and I'm satisfied from hearing from the Garda Commissioner and the Chief Of Staff that we are capable and have the capacity to deal with any eventuality," the Minister said