The blanket of flowers engulfing Martin Place continues to grow, with thousands more tributes to the victims of this week's deadly siege added.

Hostages Katrina Dawson and Tori Johnson died along with gunman Man Haron Monis in the early hours of Tuesday when police stormed the Lindt cafe in central Sydney, ending the terrifying 16-hour hostage crisis.

Soon after, members of the public began placing bunches of flowers and letters of remembrance at a makeshift memorial in Martin Place, just metres from where the siege took place.

The memorial grew through the week as Sydneysiders laid tribute to the victims.

By Saturday, it was so large there were two separate sites, one directly outside the Lindt Cafe and another, bigger site, across Elizabeth street.

Amina Bahsoun was one of the thousands laying flowers on Saturday.

"I'm paying my respects to those who passed away, nothing like this should ever happen to anyone," said the 17-year-old, who came to Martin Place with around 15 other young Muslim Australians.

"Paying respects to those who lost their lives is what any human would do who has humanity left."

Mariam Hamad, 17, also brought flowers, making the trip in from Condell Park, in Sydney's west.

The victims of the siege were "like our family too", Ms Hamad said.

"So if their lives were lost it's like someone from our family were lost.

"It's a shock to us, all Australians are united when it comes to a tragedy like this.

Andrew Silcock, from Leichhardt, was in Martin Place handing out badges inscribed with the message #Illridewithyou.

"The tragedy is horrible ... but this won't defeat us," Mr Silcock, 37, told AAP.

"It's really genuinely emotional here, I had no idea I was going to be affected in this way."

The NSW government has plans to compost the floral tributes for a future memorial site to the siege victims.

© AAP 2014