Jimmy Nesbitt in Disappeared event in Belfast
The Disappeared - people murdered and secretly buried by republicans during the Troubles - have been commemorated at an event in Belfast.
The victims' group Wave organised an event at the Lyric Theatre to mark International Disappeared Day.
Nine bodies have been recovered in searches to date, but seven of the Disappeared remain missing.
A patron of Wave, actor Jimmy Nesbitt, joined victims' families at the commemoration event.
Seven white chairs were placed outside the theatre as an installation to represent the seven missing men.
"There are still seven families who are here today, who have had a lifetime of loss and not knowing just where their brothers are so they can have a decent burial and they have somewhere to visit," Mr Nesbitt said.
"Today we're just making another appeal, another push for the tiniest bit of information.
"Just the tiniest piece, with the equipment they have now, could be the final piece of the jigsaw.
"Although it's a very long time ago, these are very significant events and I don't think they necessarily disappear from one's memory."
The actor said the families' pain had been increased by not being able to visit their loved ones' graves.
"It's not that long ago that I had to rush back from New Zealand because my own mother passed away," he said.
"As raw as it still is, I never-the-less had the comfort, and will always have the comfort, of knowing where she is buried and I can always visit her.
"There are people here today who just don't have that opportunity."
He said the families' stories highlighted the unbelievable pain they had gone through.
"One of the people we have here today, Philomena (McKee), her mother spent a lifetime with an empty chair in her kitchen - Phil lost her brother (Kevin) in 1972 when she was nine," he said.
"Every night there would be an empty place and her mother would give the children a plate of dinner to take up to the hotpress to keep it warm in case he came home.
"You can only imagine what damage that does and eventually Phil's mum suffered greatly from mental illness and I think Phil would say part of her mother died that night that he was abducted."
Kevin McKee, who was 21 when he was abducted from west Belfast in October 1972, has never been found.
"I really think there is a responsibility from those who have only the very kernel of a memory of something that happened, there is a responsibility to come forward with this," Mr Nesbitt said.
In 1999 the IRA admitted - after years of denials - that they had abducted and killed nine of the Disappeared, although they are suspected of being responsible for more of the murders."
Thursday also marks the 13th anniversary of the founding of the Independent Commission for the Location of Victims' Remains (ICLVR).
The ICLVR was established in 1999 by an intergovernmental treaty involving the British and Irish governments.
The aim was to find a way to gather confidential information which would help to find the bodies.