Police have released new CCTV images of the Manchester bomber after the mother of the youngest victim of the attack was taken off life support and told about her daughter's death.
Officers are asking for the public's help in piecing together what happened in the lead-up to the atrocity at the Manchester Arena last Monday in which terrorist Salman Abedi killed 22 people.
Detective Chief Superintendent Russ Jackson, head of the North West Counter Terrorism Unit, said "significant progress" was being made in the investigation, but added that police were still trying to establish why Abedi went to the Banff Road area in Rusholme.
Meanwhile, following claims that warnings about Abedi were not followed up, officers have been unable to find any records of calls to the police anti-Terrorist Hotline regarding Abedi before the events of May 22.
Police have asked for anyone who called them about the bomber before the attack to get in touch.
The new CCTV images come after the mother of eight-year-old victim Saffie Roussos, from Leyland, Lancashire, was said to be now "aware of the situation".
Saffie was at the Ariana Grande concert with her mother Lisa and older sister Ashlee Bromwich, who is in her 20s, who were both taken to hospital.
Mrs Roussos was reportedly in a critical condition initially and on a life support machine.
In a post on Facebook group Leyland Memories, family friend Mike Swanny said Mrs Roussos was now awake and out of surgery.
He praised the bravery of Mrs Roussos and Saffie's father Andrew, saying: "I am very proud of the strength that Lisa and Andrew have as a couple their bravery though (sic) this is commendable.
He added: "Now they can start to deal and rebuild their lives, I hope this news will make everyone smile as this is the best news we've had through this tragedy."
Mr Swanny told the Lancashire Evening Post: "Lisa's pulling through. She was in a critical condition at first, but she came off life support on Saturday and was up and talking on Sunday. She's aware of the situation with Saffie.
"She's still in hospital, but she's moving her legs, which is fantastic."
Speaking about the new CCTV images, Mr Jackson said: "We are still working to track the movements of Salman Abedi and have already released a number of images of him, in the hope that they will jog people's memories.
"We are releasing further images of Abedi, so I would ask you to look closely at them and contact us if you saw him.
''We know that Abedi left the country on April 15 and arrived back on May 18 and we now know from our inquiries that he purchased parts for the bomb after arriving back.
''What we still need to understand is if he had any of the bomb parts in his possession before he went out of the country, this is why we are tracking his movements so carefully.
''We have made a lot of progress in this with the use of CCTV and have received some really helpful calls from the public. This has led us to the Banff Road area in Rusholme."
Mr Jackson said officers had been conducting house-to-house inquiries but were "still not satisfied" why Abedi went there and said it was "vital" they understood exactly where he went and who he spoke to in the final days before the attack.
He added: "We need the public's help in this. If you have previously called and have information, I would urge you to call again.
"We need your help as we piece together what happened in the lead-up to the attack and if Abedi was helped by anyone.
''Did you see Abedi in the Rusholme area between 18th and 22nd May? Do you have any information about his movements on these dates?
''You may think it's insignificant, but it could be a key piece of information to assist us. We need your help as we piece together what happened in the lead-up to the attack and if Abedi was helped by anyone."
Greater Manchester Police confirmed that 10 men, aged between 18 and 44, remained in custody on suspicion of offences contrary to the Terrorism Act.
Six people - including a 15-year-old boy, a 34-year-old woman and four men - have been released without charge after being arrested by officers investigating the attack.
Earlier this week, police released further details about Abedi, 22, including that he had bought most of the key component parts of the suicide bomb in the few days before the attack.
Many of his movements and actions in the four days after his return to the UK from Libya leading up to the May 22 atrocity were also carried out alone but detectives have not ruled out that he was part of "a wider network".
Meanwhile, about 600 stewards will be on duty at Sunday's Ariana Grande benefit concert, according to Greater Manchester's police chief, who said security on leaving music events and football matches would have to be reviewed.