Cries of "free the refugees" and "refugees are welcome here" echoed as 1000 to 1500 people called for Australia to end its policy of offshore detention and accept people sent to Manus Island and Nauru.

Mr Haidari, a Hazara man who fled Afghanistan, told the crowd gathered in Garema Place that he had lost his father, brother and friends to persecution and that he was in danger every day.

He began a journey through India, Malaysia and Indonesia, eventually arriving on Christmas Island in 2012 speaking little English. On a boat he described as "broken", with no food and scant water, his five-day journey to Australia had him fearing for his life.

"I was counting my life every moment, when my life would end without seeing my family again," he said.

While many asylum seekers went to Manus Island and Nauru, Mr Haidari was sent to Tasmania and eventually granted a bridging visa. Later, another visa brought him to Canberra where he works at ANU.

Protesters began the rally with a minute's silence for 32-year-old Tamil man Rajeev Rajendran, who died last week apparently by suicide after experiencing mental illness as an asylum seeker fleeing Sri Lanka and sent to Manus Island.

He was the sixth asylum seeker to die there under Australia's asylum seeker policy.

Doctors, unions, church groups and members of the ACT's Hazara community were among people marching against the policy ahead of the closure of Manus Island's regional processing centre.

Protest organiser John Minns said Australia should accept refugees who were sent to the island, where many are reported to fear for their safety if they move from the centre.

"This issue goes on and on because the policy keeps on creating havoc with these people," he said.

"People are clearly not going to be able to settle into Papua New Guinea."

After Rajendran's death was met with no government comment, Dr Minns said it was extraordinary that refugee deaths had become the norm.

"We've been trying to make the government understand that these kinds of tragedies are not only predictable, but inevitable."

Dickson's Merryn Byrne said she marched as a statement for human rights.

"People fleeing persecution shouldn't be forced to endure more horrors," she said.

"We should have some empathy for people fleeing war."

Walking among signs targeting Immigration Minister Peter Dutton, and saying "we will look back in shame", South Woden Uniting Church member Len Baglow said Australia's refugee policy was immoral.

"These people are asking for refuge, but we're not treating them like that, we're treating them like criminals."

Asylum seekers on Manus Island have received notices about the processing centre's imminent shutdown as Australia prepares to leave the island. Transfers to other accommodation are to happen before October 27.