Martin Place transformed as city pays tribute

The entire nation is mourning as one of Australia's most iconic meeting places becomes flooded with floral tributes after two days of unprecedented events.

Passers-by expressed heartfelt words as they gathered to grieve for the lives of two hostages lost after Sydney cafe siege ended in tragedy.

Two hostages killed were hailed as heroes "willing to lay down their lives so others might live" in a church service mourning their deaths.

Tori Johnson, the 34-year-old manager of the Lindt chocolate cafe where the crisis unfolded, and 38-year-old barrister and mother-of-three Katrina Dawson died as heavily-armed police ended the 16-hour stand-off.

• The Sydney siege as it happened

• WATCH: The moment the siege broke on live TV

• The man behind the siege: Who is Man Monis?

• Why Martin Place was chosen

• Mother receives chilling text from son in siege

• PICTURES: A city in lockdown

• Explainer: This is not an Islamic State flag

• Rupert Murdoch's insensitive siege tweet

Yesterday, at a prayer service in St. Mary's Cathedral about 500 metres from the cafe, Archbishop Anthony Fisher spoke of how the "heart of our city is broken by the deaths of two innocents".

"Reports have emerged this morning of the heroism of the male victim of this siege," Fisher said.

"Apparently seeing an opportunity Tori Johnson grabbed the gun, tragically it went off killing him. But it triggered the response of the police and eventual freedom for most of the hostages.

"Reports have also emerged that Katrina Dawson was shielding her pregnant friend from gunfire. These heroes were willing to lay down their lives so others might live."

New South Wales Deputy Police Commissioner Catherine Burn did not confirm reports of Johnson's tussle with the gunman, adding that investigators were still compiling the chain of events that led to the siege ending.

Johnson's parents, in a statement shared via Sydney broadcast journalist Ben Fordham, praised their "beautiful boy" and called for everyone to "pray for peace on Earth".

"We are so proud of our beautiful boy Tori, gone from this earth but forever in our memories as the most amazing life partner, son and brother we could ever wish for," the statement said.

"We feel heartfelt sorrow for the family of Katrina Dawson.

"We'd like to thank not only our friends and loved ones for their support, but the people of Sydney; Australia and those around the world for reaching out with their thoughts and prayers."

Dawson, a rising star in the legal fraternity, would be greatly missed by her colleagues and friends, the NSW Bar Association said.

"Katrina was one of our best and brightest barristers who will be greatly missed by her colleagues and friends at the NSW Bar," it said in a statement.

"She was a devoted mother of three children, and a valued member of her floor and of our bar community."

Teenager Jarrod Morton Hoffman delivered a number of messages from inside the siege in Martin Place to radio station 2GB, detailing the explosive anger of gunman Man Haron Monis after a number of hostages managed to escape.

“He says an eye for an eye; if someone else runs, someone dies” Jarrod said.

“I have had a shotgun put at my head and all (he) wants is (the demands met).

"We are all afraid, I don’t think you have ever had a shotgun placed at your head. Yes, we do need help, but that will only happen if demands are met. We have been treated very well."

“He’s coming now. Bye.” - and the call was abruptly ended.

One by one dignitaries joined thousands of mourners at a makeshift memorial near Sydney's Martin Place on Tuesday, honouring those who died at the Lindt cafe.

A cordoned-off area for the shrine was increasingly widened as the number of floral tributes keep increasing.

Long faces, glassy eyes, bowed heads and people with tightly crossed arms, almost hugging themselves, consoled each other near Martin Place.

"There are all sorts of people here today, - young people, old people, locals, workers, visitors, dignitaries - it is the one place they have gathered together to show symbolically how they feel about this atrocity that has occurred in our beautiful city," said 7News Sydney reporter Anne Sanders.

"They are wearing their hearts on their sleeves and they just feel this is the only way they can express their sympathy for the loved ones and the victims of this terrible disaster."

Hundreds also left messages in condolence books set up on black trestle tables to the side of the shrine.

Set up by the premier's office shortly after Mr Baird's visit, the dozen notebooks carry the tear-stained messages of the public.

They will be bound into a NSW government condolence book.

"Innocent lives lost, family and others burned forever. Thoughts and prayers with you all" was one message.

"Rest in peace Katrina, love to Paul and your beautiful children. Rest in peace," was another.

A woman broke out into song in front of the shrine, urging the crowd to sing Amazing Grace with her.

"They didn't deserve to die, so sing it with me," she urged as other mourners joined in the wavering hymn.

NSW Police Commissioner Andrew Scipione also visited Martin Place to see the tributes left to siege victims.

"It's incredibly sad, I've got to say I don't think I could be sadder," he said.

"Having said that, I'm completely proud of our police and what they have done to keep us safe, I've got nothing but praise for them."

As tributes pile up and grief sets in for victims of the Sydney cafe siege, attention is turning to how a lone gunman with an extensive criminal history was free on bail to commit a shocking act of terror.

The gunman who held Katrina Dawson and Tori Johnson hostage along with 15 others was Man Haron Monis - a 50-year-old self-styled Islamic cleric well known to police who arrived in Australia as a refugee from Iran in 1996.

He also died in the siege that left two hostages dead and six other people were injured.

Monis was already on bail after being charged with being an accessory to the murder of his ex-wife in 2013 and his bail was continued when dozens of indecent and sexual assault allegations were brought against him earlier this year.

Police and paramedics tried desperately to save hostages wounded during the violent final moments of the 17-hour operation.

Seven Network reporter Chris Reason, who was watching from the Seven newsroom after being allowed back in as night fell, watched from less than 50 metres away as police stormed the café.

The gunman was attempting to shepherd hostages from one side of the café to the other, when a small group broke away and ran for the exit, Reason said.

One man with his hands raised ran towards police and threw himself on to the pavement where he was quickly searched by two police, before being helped away.

Six minutes later, a group of five hostages ran from the Martin Place exit, fleeing to safety.

It was unclear exactly what prompted the rapid escalation, but it was reported gunman Man Haron Monis fired his shotgun.

Reason said a call came from police communications that there was a “hostage down”, prompting the officers to storm the building without warning.

Percussion grenades designed to create loud flashes and bangs and disorient their targets, were tossed into the room. They lit up the windows where the hostages had been forced to hold an Islamist flag in the first hours of the siege.

As police stormed the building, gunshots rang out and officers equipped with night vision goggles filed into the room from two entrances.

The two groups of police converged on the gunman, who was believed to have been killed in the fire fight.

Dozens of police then ran to help hostages as they fled the smoke-filled room.

One woman, shoeless and injured was carried away by two police officers.

Ambulance officers, who had been on standby inside the exclusion zone, sprinted toward the building with stretchers, and took at least five people away, working on them as they ran back to waiting ambulances.

A number of stretchers were wheeled into the building, however, it was unclear how many people may have been injured.

The gunman was earlier named as 'Sheikh' Man Monis.

Monis is infamous for sending hate mail to the families of Australian soldiers killed in Afghanistan.

The letters were highly offensive, comparing the fallen soldiers to pigs.

Charged with using the postal service to harass and offend, he claimed to be a peace activist, chaining himself to the courthouse steps at one point.

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He was sentenced to community service, and placed on a two-year good behaviour bond.

Monis was born in Iran; he is aged around 50 and came to Australia as a refugee in 1996.

Apart from the letter-writing campaign, he's also been implicated in murder.

He was charged last year with being an accessory to the murder of his ex-wife, who was stabbed and set alight in a stairwell.

This year he was charged with the sexual assault of a young woman who had gone to him for so-called 'spiritual healing'.

He's currently on bail.

Monis plunged Sydney into lockdown chaos after taking control of a Lindt cafe in Martin Place.

Several prominent buildings were shut down in and around the area, where an undisclosed number of people have been held hostage in a Lindt Cafe since Monday morning.

The faces of customers and workers were pressed up against a shop window of the Lindt Chocolate Cafe.

They had their hands in the air and their eyes closed. And were made to hold up what is believed to be an Islamic State flag.

The 7News Sydney newsroom, which faces the cafe under siege, had been evacuated by police.

An Islamic flag - black with white writing on it - has been held up to the glass.

In a chilling drama unfolding in the city centre, Martin Place was shut down and scores of police are surrounded the cafe.

Trains between Central Station and Bondi Junction station were stopped while buses were diverted away from the area.

Martin Place was initially named as a potential target during terror raids earlier this year.

For general information about the siege at Martin place – call the Public Information and Inquiry Centre: 1800 227 228

To report any suspicious activities – call the National Security Hotline: 1800 1234 00

For transport updates – call: 131 500

For emergencies – call: 000