A woman thanks a police officer near the scene of the tragedy. Source: News Corp Australia

The 17-hour stand-off at the Lindt cafe involved NSW police officers as well as members of the state Public Order Riot Squad, Dog Unit, Negotiators, Aviation Support Branch, Police Rescue and elite Tactical Operations Unit.

Now, Sydneysiders and the rest of the world are mounting a campaign to express their thanks to all those who risked their lives.

Police officers write condolence notes in Martin Place. Source: News Corp Australia

Heavily armed police stormed the Lindt cafe after they heard gunshots. Source: News Corp Australia

A hostage runs to an armed tactical response police officers after her escape. Source: AP

A Facebook page has declared this “Say Thanks to the Cops Day”, and members of the public have been stopping police in the street to express their gratitude.

One officer was clapped and cheered when he went into a McDonald’s in a western Sydney suburb for food, said a spokesperson for NSW police.

“Most people have been really, really supportive,” he said, “Members of the public have been approaching police on the street and there’s been a fair amount online.”

Hawkesbury Local Area Command posted a photo of a bouquet on their Facebook page, thanking the anonymous gift-giver.

The 39-year-old officer who was taken to hospital with facial wounds from shotgun pellets came in for special praise after he vowed: “I’ll be back at work tomorrow”.

NSW Police Deputy Commissioner Catherine Burn was also honoured for her unflappable calm as the public face of this tragedy.

Commissioner Andrew Scipione said yesterday that about 70 interviews would be conducted.

The role of the police is far from over. Special officers are planning a nighttime reconstruction of the horrific crime, others are watching over the public in Martin Place, and the NSW police band even performed by the makeshift memorial to send a message of hope to people paying tribute.

The Facebook page read: “Despite the horror of the Sydney Siege that took place overnight one thing stood out that represents a shining light for our way of life. That is the professionalism and bravery shown by the Police Officers who worked non stop for the entire 17 hour siege.

“When watching footage of these guys storming into the Lindt Café it is important to remember that they are not just police officers. They are husbands, wives, fathers, mothers, sons and daughters. They are just ordinary people like you and I putting their life on the line for us.

The scene in Sydney city centre, where well-wishers have shown strong support for police. Source: News Corp Australia

“Please take just two seconds out of your day this Friday to say ‘thanks’ to the police that work hard to keep you safe. These guys play an important part to our society and deserve to see how much we appreciate them.”

Many commented on their incredible bravery, while Christopher Quinsey wrote: “Easily one of the hardest and most thankless jobs going round.”

Linda Garner added: “Thank you for your dedication and hard work. You all deserve a medal.”

The creator of the page, Joseph Del Duca, told news.com.au: “We are really encouraging people to thank the cops in anyway they feel comfortable. Be it a handshake, a nod or offering to shout them a coffee.

“My four-year-old niece is currently working on a thank you card she can hand to a police officer if she sees one tomorrow.”

More than 26,000 social media users have vowed to make Saturday a day of light, to remember the victims of the siege.

And the NSW government has set up an online condolence book for those who cannot make it to Martin Place.