A Belfast book of condolence has opened in a “clear and positive” show of solidarity with Nora Quoirin’s family.
Sinn Fein Lord Mayor John Finucane was the first to sign at the city hall, followed by a queue of other elected representatives and well-wishers.
Nora’s mother Meabh is from Belfast.
Mr Finucane helped lead a long campaign for answers about the death of his murdered father, solicitor Pat Finucane, and said he hoped Nora’s family would receive the truth.
He said: “This is a story that has resonated with and struck home in Belfast.
“It is heartbreaking. I don’t think this is something that would be easily dealt with in any circumstance but the fact that they are so far away from home in Malaysia.”
He added: “This is a family that was on holiday, this is a girl who was vulnerable and I think the family have been through hell in the past few days.
“Whilst she had not been found everybody hoped that she would be found safely and it really is a very tragic story.”
He praised the “clear and positive” show of solidarity from the Belfast public.
A special service was held on Tuesday at the South Belfast church which Nora was baptised in. Her grandparents are parishioners.
Mr Finucane added: “There is a very clear connection to Belfast and I think the empathy and support and the story itself has really touched something in Belfast.
“You can see that from the messages of solidarity and support from the people of Belfast.”
Padraigin Drinan has campaigned on human rights issues including the murder of solicitor Rosemary Nelson.
She awaited her turn to sign the book inside the entrance of a city hall constructed in the late 1800s.
“I don’t know them, I don’t know anything about them, but to have a post-mortem for eight hours and come to no conclusion, everything gets worse and worse.”
She added: “If things could get worse that was it.”
David Hynds said it was important to come to mark a “horrific” tragedy.
He said: “I feel terribly sad for the family, being so far away.
“There was no way of not coming, I made a deliberate effort to come down.”
He added: “It is such an awful tragedy what has happened.”
He praised the donation of a reward for information about Nora’s disappearance by a Belfast business.
“It really did show the way that people do react, to sympathise with somebody.
“You have to show empathy with people.”