Australia's prime minister laid flowers at a makeshift memorial in Sydney today for the victims of the cafe' gun siege which left three people dead, including a mother of three.

Tony Abbott laid a white floral bouquet at the memorial in Martin Place while his wife Margie laid a bouquet of red flowers. Mr Abbott also wrote a message and waved at the crowd but did not address them.

Hundreds of people have been leaving flowers at the memorial.

Seventeen people were held hostage at the Lindt Chocolat Cafe yesterday. The siege ended 16 hours later in a barrage of shots that left two hostages and Iranian-born gunman Man Horan Monis, 50, dead, and a nation that has long prided itself on its peace rocked to its core.