Family members said a prayer and marched to the steps of Parliament where they laid a black wreath with five white lilies.

Four of the lilies represented each of the four remaining Missing, and one for the missing Lisa Dorrian.

It has been almost 20 years since she was last seen at a caravan park party in Ballyhalbert, County Down. Police believe she was murdered.

No one was ever convicted and despite numerous land and sea searches, his body was never found.

His father, John Dorrian, told BBC News NI that joining other families brought him some comfort.

“Coming here for this walk, it helps us meet other people who are in the same situation and we try to support each other,” he said.

“As a family we feel sorry for the people who have also lost people because we know how they feel. I know these people have been missing since the 70s. It must be terrible.”

Anne Morgan, whose brother Seamus Ruddy was among the missing and whose remains were found in 2017, also attended the march.

“We found that being together helped us be heard,” she said.

The walk is organized by Wave Trauma Centre, which has supported the families of the missing since the mid-1990s.

The organisation’s chief executive, Dr Sandra Peake, said: “One of the evil aims of those behind the disappearances of people was to literally wipe every trace of them from the face of the earth as if they had never existed.

“The inhumanity is breathtaking.

“Until all the missing return home, the families will not rest or remain silent.”