The Sydney shopping centre where six people died after a “senseless” attack has become a site for solemn reflection as hundreds gathered to mourn those killed inside, while Australian Prime Minister Anthony Albanese has raised giving citizenship to an immigrant security guard who was wounded while confronting the knife-wielding attacker.

The doors of Westfield Bondi Junction, in the city’s eastern suburbs, re-opened to the public on Thursday for the first time since a mass stabbing attack during Saturday afternoon trade.

The deadly rampage through the mall was the earlier of two knife attacks by lone assailants over three days that have traumatised Sydney.

Joel Cauci, the man who stabbed 18 people in Saturday’s attack, was shot dead by police. A 16-year-old boy is in police custody after he allegedly stabbed a Christian bishop and priest during a church service on Monday. Police allege the boy had a religious or ideological motivation and attacked during the streamed service to cause intimidation.

Dawn Singleton, 25, Jade Young, 47, Pikria Darchia, 55, Yixuan Cheng, 27, and 30-year-old Faraz Tahir died at the shopping centre, while Ashlee Good, 38, later died in hospital.

A person lays flowers at a memorial set up inside the Westfield Bondi Junction. – AAP

Albanese has praised those who intervened in Saturday’s attack to prevent more deaths, including Tahir's security guard colleague Muhammad Taha, who was stabbed in the stomach. Taha is from Pakistan and working in Australia on a temporary visa that is due to expire within weeks.

Albanese said his government would consider giving Taha citizenship, the same reward he had earlier offered French citizen Damien Guerot for his own heroic intervention.

“Yes, we certainly will” consider making Taha an Australian citizen, Albanese said.

“Muhammad Taha, he confronted this guy, the perpetrator, Joel Cauchi, on Saturday. And it just shows extraordinary courage,” Albanese said.

“That’s the sort of courage that we want to say thank you to, frankly.”

Guerot was nicknamed “Bollard Man” on social media after security camera footage showed the construction worker standing at the top of an escalator on Saturday and menacing Cauchi with a plastic bollard as he approached. Cauchi fled down the escalator and people on Guerot’s floor were safe.

NSW Premier Chris Minns and Police Commissioner Karen Webb sign a condolence book at Westfield Bondi Junction. – AAP

Martine Wachtenhein, 66, who was among those visiting the mall on Thursday, choked back tears as she recounted how Cauchi came within three or four metres of her before Guerot forced him back.

“I could have been one of the people stabbed,” she said, choking back tears.

“If I could send a message to that beautiful man that would be the best thing. I want to thank him. I don’t think he realises the impact it had on me – thanks to him I managed to escape.”

Guerot’s temporary Australian work visa was due to expire in July until Albanese intervened.

While Guerot had been offered citizenship, he wanted a permanent resident visa, which he would receive on Thursday, Albanese said.

The operators of the Westfield mall, about 3km (2 miles) from the city’s iconic Bondi Beach, allowed residents enter to pay their respects to the victims on Thursday, with stores remaining closed and a white floral tribute laid out on the second floor.

A sombre-faced NSW Premier Chris Minns and Police Commissioner Karen Webb walked through the centre before addressing the media.

“It is not back to normal for Sydney, but this is an opportunity to get some kind of grieving and to turn the page on what has been a very difficult period,” Minns said.

The premier praised the community for coming together and described the day of reflection as “the first step in healing”.

“We are a community that can stand together in difficult periods and show that grief is universal when it is felt by one family, one individual,” he said.

Vinny Jovanovski, 33, who owns a cafe on the fifth floor where the attack happened, stands near flower tributes. – Reuters

Many wept as they walked though the halls, with advertisements on digital screens replaced by black ribbons.

Normal trading will resume on Friday, while a candlelight vigil at the beach on Sunday will mourn the victims, authorities said.

“It wasn’t very nice walking through there, it obviously did bring back certain flashbacks,” said Vinny Jovanovski, 33, who owns the Glo Bar cafe on the fifth floor of the mall and witnessed the attacks.

“But I mean, we have a lot of love and support from the community. Everybody is being very kind to each other.”

Police are conducting major investigations into the shopping mall attack, the stabbings at the Christ the Good Shepherd Church and the riot that occurred outside the Orthodox Assyrian service as people sought vengeance over the attack.

The mall attack is not a criminal investigation, but police are gathering evidence to present to a coroner to investigate the circumstances of the deaths. Five of those slain were women and one was a male security guard.

Minns has indicated stricter knife laws would be considered following the stabbing and a separate attack at a western Sydney church.

Police Minister Yasmin Catley said the state government would also consider similar laws to those implemented in Queensland to allow officers to use metal detectors without a warrant during searches.

Members  of the Ahmadiyya Muslim Association Australia, speak about slain security guard Faraz Tahir outside the Westfield Bondi Junction shopping centre. – Reuters

Scentre Group, which owns and operates the shopping centre, said shops would open for business on Friday with an increased police and security presence.

Normal trading hours will be maintained, although some stores will opt to remain shut.

Six people remain in hospitals across Sydney, with one woman in intensive care in a serious but stable condition, according to NSW Health.

Ashlee Good's nine-month-old baby remains in hospital in a serious but stable condition.

A permanent memorial is being planned near the site and a beachside candlelight vigil will also be held on Sunday.