The New Zealand city of Christchurch came to a standstill Monday to mark the fifth anniversary of a devastating earthquake that left 185 dead, amid anger about accountability and insurance delays.

The 6.3-tremor in 2011 was one of the country's deadliest disasters and the city stopped for a minute's silence at 12:51 pm (2351 GMT Sunday) to mark the moment when much of New Zealand's second largest city was destroyed.

Throughout the day people cast flowers into the Avon River which meanders through the city in a poignant "River of Flowers" memorial, while players wore black armbands at the cricket Test between New Zealand and Australia being played at Hagley Oval.

"Today we reflect on the Christchurch earthquake, remember those we lost & look forward with optimism to the future," Prime Minister John Key said as he led tributes with a message on Twitter.

"Today we remember the events of five years ago in Christchurch and those who lost their lives. But we also reflect on how far we've come, what's been achieved and look forward to the future with a renewed sense of optimism."

However, Key's words jarred with many people angered that no one has yet been held accountable for the buildings that collapsed and not all home insurance claims have been settled.

Maan Alkaisi's wife was one of 115 people killed in the CTV building that collapsed and he has been campaigning for accountability ever since an inquiry found it did not meet construction standards.

"The fact that after five years there is nothing; how do you explain that?" Alkaisi told the New Zealand Herald.

The families of the CTV victims attempted to launch a class action lawsuit, but were informed New Zealand's justice system could not support such a case, Alkaisi said. They were told police were responsible for finding criminal liability.

- Protest rally -

Ann Brower, the only survivor among nine people on a bus crushed under a collapsed building, remains furious that the local council had failed to cordon off the area after it was damaged in an earthquake five months earlier.

"It wasn't the earthquake that killed all the people on the bus, it was the building," she told Radio New Zealand.

"And it was the city council's lack of requiring the building owner to fix it, and the city council's lack of bringing it down, and the city council's lack of putting up a fence. No, no, no, it was not an accident."

A city council spokesman said they were still awaiting the outcome of the police investigation into buildings that failed and could not comment until it was completed.

On Sunday, nearly 1,000 Christchurch residents attended a protest rally to air their frustration over insurance delays.

Insurance industry critic Sarah Miles, who wrote a book about the management of the catastrophe called "The Christchurch Fiasco", said thousands of people had been affected by failed repairs, delayed settlements and cash settlements that fell short.

The government minister responsible for overseeing the earthquake recovery, Gerry Brownlee, said much of the work had been done.

"Most insurance claims are resolved, most of the demolitions are done, most of the infrastructure repair is complete," he said.

Since February 22, 2011 nearly 14,000 quakes have been recorded in the Christchurch area including 13 in the 24 hours to 12:51pm Monday.

Most of the shakes have been minor although a week ago there was a reminder of how powerful they could be when 5.8 tremor knocked items of shelves and sent a cliff face plunging into the sea.