Two years after one of the largest migration tragedies in history, a group of friends and activists are calling for a memorial on the tomb at Addolorata Cemetery where the unknown dead lie buried.

As many as 850 people are believed to have died on April 19, 2015, when a migrant boat capsized 60 miles off Libya.

Hundreds were trapped in the ship’s hold when it sank.

Despite an extensive rescue operation, only 28 people survived, and only 24 bodies were ever recovered.

The victims were brought to Malta in the days that followed, where they were given a funeral and buried in the common grave at Addolorata Cemetery.

Two years on, the tomb lies unmarked, with nothing to mark the tragic loss of life it represents.

Anthropologist Elise Billiard told the Times of Malta she was struck by the situation when she helped organise a memorial walk on the first anniversary of the tragedy last year.

“There is nothing to tell you what happened; you don’t even know where to stand,” she said. “That such a huge tragedy can come so close to us without us acknowledging it is baffling. It’s not part of our history; we dismiss it somehow.”

Together with a wide group of friends – some who are members of NGOs and others just ordinary people touched by the tragedy – Dr Billiard is raising funds for a plaque on the site.

That such a huge tragedy can come so close to us without us acknowledging it is baffling- Elise Billiard

Although the names and nationalities of the victims are unknown, Dr Billiard likened the proposal to international memorials for the Unknown Soldier, a chance to remember the tragedy and the many others who continue to die in similar circumstances.

READ: Hundreds dead as boat capsizes off Lampedusa

A commemorative sign on the grave would need permission from the authorities, but Dr Billiard said it was important to the group that the plaque came “from the people of Malta”.

“We don’t want the memorial to be in the name of any particular organisation, or even government, because a lot of the anger over this tragedy is directed at governments,” she said, adding that little effort had been made to identify the victims.

Having organised a memorial walk last year, the group have also extended an open invitation this year for people to visit the site of the tomb on or around April 17 and leave flowers or candles as a sign of remembrance and condolence.

Amendment: A previous version of this article incorrectly used the term 'hundreds' in the headline. The error is regretted.