Members of the British Muslim Forum and religious leaders from Christian and Jewish faiths pay their respects at St Ann's square in Manchester, England Sunday May 28, 2017.
Police said the attacker had the suitcase in at least two Manchester neighborhoods.
The authorities are now handling 500 terror-related investigations into 3,000 individuals, with another 20,000 people on the radar posing a "residual risk".
FILE - In this August 28, 2016, file photo, Ariana Grande arrives at the MTV Video Music Awards at Madison Square Garden in NY.
Abedi detonated a bomb on 22 May at the end of a concert by United States singer Ariana Grande.
Britain's MI5 intelligence service yesterday launched an internal inquiry into whether vital clues were missed in the run-up to the Manchester suicide bombing, as police arrested another man in connection with the attack.
"We have also have a good understanding of the likely component parts of the bomb and where these came from", said Jackson. Prime Minister Theresa May last Saturday lowered the terror threat level, which had been hiked after Monday's carnage.
Police are seeking the public's assistance in locating the suitcase.
Ariana's mom always has extra security around her property when Grande returns home to protect her from overzealous fans, though the decision to up the amount of people watching over the home in the wake of the bombing was reportedly made by Florida police.
The railway station next to Manchester Arena, which had been shut since the blast, reopened Tuesday, easing transport woes for residents.
The station, which is connected to Manchester Arena where the bomb went off, suffered structural damage in the incident.
Burnham said the city had pulled together "through what has been our darkest week".
Police also released a CCTV image on Monday of the bomber carrying a blue suitcase as they try to trace his movements.
Police are urgently poring over CCTV footage of Salman Abedi in the week leading up to the attack on 22 May, as they continue to establish whether he was part of a wider terror network. He died when the bomb he was carrying in a knapsack exploded among the concert crowd.
Counterterrorism cops have arrested suspects around Greater Manchester - and as far away as Warwickshire and Sussex - since the atrocity.
Abedi's family will not be able to receive the remains of his body as his father Ramadan, his mother Samia and his younger brother Hashim are all in Libya.
A British counterterrorism official told CNN it was not clear whether Abedi received training with ISIS in Syria.
Manchester bomber Salman Abedi had a "relatively minor" criminal record as a teenager but he was not known to police for holding extremist views. If you would like to discuss another topic, look for a relevant article.