Tears flow at Christchurch's CTV building site

A display has been set up at Christchurch's CTV building site where people can place flowers. Photo / Supplied

Tears are already flowing at Christchurch's CTV building site where 115 people lost their lives five years ago today.

Loved ones of those who died are sticking close to each other as they lay flowers at the site of the greatest loss of life during the 2011 February quake.

Following a request from the families, a display has been set up where people can place flowers.

It includes tissue boxes for those overcome with emotion at the site.

Across the road, at the white chair memorial, a red flower has been placed on each of the 185 chairs -- the number of people that died on the day -- and members of the public have also been laying flowers there.

At the white chair memorial, a red flower has been placed on each of the 185 chairs -- the number of people that died on the day. Photo / Supplied

The Prime Minister has a message for the people of Christchurch this morning, the country stands alongside you.

John Key joins a number of dignitaries including Governor-General Sir Jerry Mateparae in the city today, taking part in the earthquake commemoration service from midday.

The Prime Minister told Newstalk ZB's Chris Lynch the country is behind Canterbury -- and shares the hopes and aspirations for Christchurch.

Mr Key also acknowledged the frustrations residents of the city faced but says the Government is genuinely doing everything it can to try to get those issues resolved.

Earlier the commemorative River of Flowers opened in Christchurch.

People can throw flowers into the Avon River, from 8am to 8pm, at 19 official sites around the city to mark the five year earthquake anniversary.

Dozens of people are expected to make the floral tribute over the next 12 hours.

One site, at the Places of Tranquility Gardens in the central city, is just metres away from the PGC building site where 18 people lost their lives.

Fresh flowers have already been laid there with a note saying "I'm so sorry we couldn't have been with you on that day, even though we tried our best.

Flowers and notes have already been laid at the PGC building site this morning #feb22 @NewstalkZB pic.twitter.com/ls5mkmPYHi

— Charlotte Lewis-West (@clewiswest) February 21, 2016

Newstalk ZB reporter Lesley Murdoch is in Christchurch talking to locals.

New Brighton community leader Tim Sintes told Ms Murdoch that before the earthquake there were about 16,000 people living in the area.

Now there were only about 6000 people left, he said.

Sintes said it was "extremely hard" to see the amount of progress in New Brighton compared with other areas of Canterbury and Christchurch.

"We need a sign to show money is being spent in the area ... so people can see the council cares."

Nationwide flash mob for today's earthquake anniversary needs another 500 people to sign up in the next two hours in order to launch.

Participants donate space on their social media walls to share the message "Let's stand united with Christchurch. Kia kaha. We will not forget."

Social media tool Get Behind It will post the message on people's feed at the exact time the quake struck Christchurch.

Founder Becky Siame was hoping for one million participants to show their support for Christchurch.

She has about 500 people already, and needs another 500 to launch.