Police want to know what was in Manchester bomber's blue case

Authorities in the UK have released an image of suicide bomber Salman Abedi carrying a distinctive blue suitcase on the day of the deadly Manchester attack, as they continue to track his final movements.

Greater Manchester police said they are particularly interested in his whereabouts between May 18 up to the day of the bombing on May 22.

People who may have seen the suicide bomber during that time with the suitcase are being urged to come forward.

"Today, we are releasing an image of [him] carrying a distinctive blue suitcase and an image of a replica of the case," said Detective Chief Superintendent Russ Jackson from the North West Counter Terrorism Unit.

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

“We believe Abedi was in possession of this case in the days before the attack at Manchester Arena on Monday 22 May."

"I want to stress that this is a different item than the one he used in the attack. This image was taken from CCTV in the city centre on 22 May."

In a statement from authorities, people who might come across the case are being urged not to approach it.

Detective Chief Superintendent Russ Jackson from the North West Counter Terrorism Unit said: "We have no reason to believe the case and its contents contain anything dangerous, but would ask people to be cautious."

"This remains a live investigation and if you have any images or footage you believe can assist us then please upload them to UKpoliceimageappeal.co.uk or UKpoliceimageappeal.com as soon as you can."

New security pictures have also emerged reportedly of Abedi inside a convenience store on the day of the attack.

BBC reports the footage was taken at a shop near to the apartment where the bomber had been prior to the incident.

Fourteen men have now been arrested over the attack.

It is reported that 1000 officers are involved in the investigation into the deadly incident, with the police presence is still heavy in Manchester.