Church services in Sydney drew politicians and faith leaders together as the country showed solidarity with New Zealand following the Christchurch terror attacks.
The death toll from the attack on two mosques on New Zealand's South Island on Friday - allegedly carried out by sole Australian gunman Brenton Tarrant - has risen to 50 people, with at least 50 people injured.
Tarrant, 28, from Grafton in NSW, has been charged with murder and remanded in custody until April 5.
On Sunday Prime Minister Scott Morrison attended two church services in Sydney with other politicians and religious figures.
Mr Morrison arrived at St Mary's Cathedral in the city on Sunday afternoon for an interfaith service of remembrance.
NSW Premier Gladys Berejiklian, state Opposition Leader Michael Daley, the Governor of NSW David Hurley, Deputy Opposition Leader Tanya Plibersek, NSW and Sydney Lord Mayor Clover Moore also attended the service.
The Grand Mufti of Australia Dr Ibrahim Abu Mohammed, the Catholic Archbishop of Sydney Reverend Anthony Fisher and the New Zealand Consul General to Australia Bill Dobbie all addressed the congregation.
Rev Fisher told the congregation they stood together "in solidarity with our Muslim brothers and sisters, in their grief, horror and disgust".
The Grand Mufti said the perpetrator of the attack "will not divide us".
Earlier in the day the prime minister gathered with about 200 parishioners at St Mark's Coptic Church in Arncliffe in southern Sydney with his wife Jenny Morrison and their two daughters.
The sails of the Opera House were lit up on Saturday night with the Silver Ferrn a day after Muslims were massacred while worshipping at mosques in Christchurch.
The alleged gunman's family approached NSW Police after viewing footage of the terror attack.
He posted a 74-page "manifesto" online before the attack, and a 17-minute video was also uploaded of him arming himself and entering a mosque where he started shooting.
"My understanding is the family (of this man) did approach NSW Police after the incident was on TV," NSW Police Commissioner Mick Fuller said in Sydney on Saturday.
Mr Fuller has asked people not to watch Tarrant's "disturbing" vision of the massacre circulating online.
NSW Police are conducting a "two-pronged investigation" which involves assisting New Zealand agencies and making sure the Australian terrorist "hasn't slipped through the cracks", Mr Fuller said.
He said there were "no active threats" in NSW linked to the shooting, however the national terrorism threat level remains at "probable".
The commissioner joined other senior police at an 80-strong meeting with religious leaders, including Grand Mufti Dr Ibrahim Abu Mohammed, at the Australian National Imams Council.
Police patrols and visits to mosques around Sydney's metropolitan area have been increased and will continue in the coming days and potentially weeks.