An image released by police shows Manchester bomb suspect Salman Abedi carrying a blue suitcase in the city centre on the day of the bomb attack that killed 22 people.
Detective Chief Superintendent Russ Jackson from the North West Counter Terrorism Unit said he hoped the CCTV still image would spark people to come forward and give information over his movements between 18 and 22 May.
"We know he visited the Wilmslow Road area of Manchester and was also seen in Manchester city centre with the blue suitcase. If you have any details about the suitcase we need you to get in touch and let us know.
"This is a different item than the one he used in the attack.
"We have no reason to believe the case and its contents contain anything dangerous, but would ask people to be cautious," he said.
Earlier on Monday (29 May) police with dogs searched a house in the Rusholme area of south Manchester while another search is taking place at a the Viridor Waste Management landfill in Bury, Sky News reported.
Officers searched a flat in Shoreham-by-Sea, West Sussex with a 23-year-old man becoming the 14th person to be held by police over the suicide bombing during an Ariana Grande concert at the Manchester Arena.
MI5 has launched a second investigation into claims that the Manchester bomber was repeatedly flagged to authorities for his extremist views.