FORENSIC searches centred on a Bury landfill site in the hunt for more clues to the Manchester Arena atrocity.

Suicide bomber Salman Abedi left 22 dead and injured more than 100, after the blast at the end of an Ariana Grande concert.

Police investigating the terrorist attack were combing a Viridor Waste Management site, off Pilsworth Road, in Pilsworth, on Monday.

A number of police staff in white forensic suits searched the site and a large red-and-white tent was set up to protect part of the site.

Police also released a CCTV image on Monday of the bomber carrying a blue suitcase as they try to trace his movements.

The CCTV still picture was taken in Manchester city centre on the day of the attack last Monday, which claimed the lives of seven children.

As it stands, 16 people have been arrested in connection with the investigation, of which five people have since been released without charge.

A total of 11 men remain in custody for questioning.

More than 1,000 officers are working on the investigation to piece together what happened on the night of the attack and to find out whether others have been involved.

Detective chief superintendent Russ Jackson from the North West Counter Terrorism Unit said: "We continue to track the final movements of Salman Abedi and are particularly interested in his whereabouts between May 18 and 22, 2017.

“We know he visited the Wilmslow Road area of Manchester and was also seen in Manchester city centre with the blue suitcase.

““We have no reason to believe the case and its contents contain anything dangerous, but would ask people to be cautious.

“The public should not approach the case if they see it but contact police immediately on 999."

Detective Chief Superintendent Russ Jackson, head of the North West Counter Terrorism Unit, said: “We are now more than seven days into the investigation into the tragic events of last Monday night at the Manchester Arena.

“We have had over one thousand officers working on this investigation to piece together what happened and to understand if others have been involved. We also continue to support the families of those bereaved and the injured and our thoughts continue to be with them.

“The scale of the investigation is enormous with over 7,000 entries on our actions log, which captures our lines of enquiry, within the Counter Terrorism Control room. We have almost 300 pieces of digital equipment, including phones, which we are working through and hundreds of witnesses to contact and take statements from.

“Much of the investigation has been painstakingly working through Salman Abedi’s last movements. We have done this by examining his movements on CCTV and other interactions he has had whether it be with people or the phone calls he has made.

“With specialist support we have also have a good understanding of the likely component parts of the bomb and where these came from.

“Our enquiries show Abedi himself made most of the purchases of the core components and what is becoming apparent is that many of his movements and actions have been carried out alone during the four days from him landing in the country and committing this awful attack.

“It is vital that we make sure that he is not part of a wider network and we cannot rule this out yet. There remain a number of things that concern us about his behaviour prior to the attack and those of his associates which we need to get to the bottom of.

“We are especially keen to find out why he kept going back to the Wilmslow Road area and we need to find the blue suitcase which he used during these trips.

“We still have a number of people in custody and we will be seeking to extend the custody of some of them as we work to understand what has gone on and whether Abedi was helped.

“Today we have released without charge two men aged 20 and 24 from the Fallowfield area and a 37-year-old man from the Blackley area.

“The release of some people can be expected in investigations of this nature as we corroborate accounts that have been provided.

“There has been huge progress made over the week and the speed of the inquiry remains the same. It will be a long investigation and it will take considerable time before we fully understand what has happened.

“We continue to appeal for the public’s help in tracking Abedi’s movements. Calls to us have already significantly helped our understanding of where he has been and what he has had in his possession.”

Anyone with information should call the Anti-Terrorist Hotline in confidence on 0800 789321. If you have any images or footage that you believe can assist us then upload them to Ukpoliceimageappeal.co.uk or Ukpoliceimageappeal.com.