Slain asylum seeker Reza Berati remembered by 15,000 people who have attended vigils across Australia.

Thousands of people have lit up the night skies with candles across Australia at vigils to remember slain Iranian asylum seeker Reza Berati and to call for an end to secrecy on refugees.

Organiser of the event GetUp! estimated 15,000 people attended vigils in several capital cities, with about 5000 in Melbourne and 3000 in Sydney.

The vigils come days after Mr Berati, 23, was killed and 62 other asylum seekers were injured in violence at the Australian-run immigration detention centre on Papua New Guinea’s Manus Island.

“The truth is we just don’t know what’s happening in these places. The government’s shut off the lights, taking censorship to an unprecedented level,” GetUp! national director Sam McLean said.

World Vision Australia CEO Tim Costello spoke at the Melbourne vigil in Federation Square and said the people who attended across the country were doing serious moral work.

“We know asylum policy is complex, but what isn’t complex is that a human being who came to us for protection instead died in terrible circumstances,” Rev Costello said.

Father Bob Macguire, also in Melbourne, said the thousands of candles that lit up Federation Square would shine a light on the plight of asylum seekers.

Several other speakers called for the closure of Manus Island.

The gathering also shared one minute’s silence to remember Mr Berati.

GetUp! says more than 600 snap protests were organised for Sunday night, from Queensland cattle stations to Sydney’s Town Hall.

Among the 3000 at the Town Hall vigil was Emma Miller-Cockcroft, who is sick of the government’s treatment of asylum seekers, which she reckons doesn’t reflect the will of many Australians.

“If your own government doesn’t respect human right to life then … it’s just a disgrace. It’s embarrassing,” the 28-year-old told AAP.

“It’s important that the world knows not all Australians are like this. We’ve got a reputation as being quite racist.”

The “hysteria” over a couple of boat arrivals was disingenuous and ignored Australia’s history, she added.

“Some of my family came here in 1890. They didn’t drive to Australia from Europe, they came by boats.”

Xenophobic treatment of asylum seekers must stop in Australia, The Chaser’s Chris Tylor said during a brief address to the crowd.

“We have more land than anyone else and we take fewer people than anyone else. That is absolutely appalling.”

Sydney-based communications student Sarah Hunt, 34, agreed, adding that Australia was “privileged” and said the debate should centre on human rights, not which of the two major parties was less-harsh.