The Department of Foreign Affairs expects it will take another two or three weeks before it can compile an accurate list of the names of Irish victims of last Tuesday's attack in New York. The number of Irish citizens missing are now expected to be in the "low double-digits, and no more than 20", said a Department spokesman.
"Many of the names in our database have been eliminated as relatives and friends have managed to contact people they originally reported as missing.
"Many of the names remaining on the list are not thought to be critical cases." The number of Irish people confirmed dead by the Department of Foreign Affairs remains at four.
Relatives of some of the Irish victims have arrived in New York. Others are due to travel out in the coming days.
Relatives of Mr Martin Coughlan (53) from Cappawhite, Co Tipperary, who is still reported as missing, travelled to New York on Saturday. The sister of Mr Coughlan's wife, Catherine, was among those to go to New York to offer support. Speaking from Tipperary, Mr Coughlan's sister-in-law, Brigid Coughlan, said the family "were still waiting in hope".
Mr Donagh Killilea, a spokesman for the family of missing stockbroker Ms Ann McHugh (35) from Tuam, Co Galway, said her parents, Padraic and Margaret, and siblings Maura, Brendan and Pat will be in New York by next Saturday.
He said: "They're finding it very difficult being so far away from the scene. It creates a terrible feeling of helplessness. They all want to be there just to see if there is anything they can do."
Relatives of Mr Sean Canavan (39), a carpenter who was working in the North Tower when the first plane struck last Tuesday morning, are also leaving for New York this week.
His Monaghan-based sister, Ms Celine Traynor and her two-year-old son, Aidan, who is Mr Canavan's godson, and another sister, Teresa, will fly to New York on Wednesday.
They will then help members of the Canavan family in New York with the grim task of visiting morgues and calling emergency helplines in the hope of obtaining some news.
Mr Canavan's family in New York also includes another sister Kathleen and brother Ciaran. Mr Canavan, who was not married, was best man at his brother's wedding only a few weeks ago.
Mr Ciaran Canavan, also a carpenter, has been helping with rescue efforts at the World Trade Center since last Tuesday.
Mr Canavan's parents emigrated from Ireland in the 1950s. His father, Kieran, from Ballygawley, Co Tyrone, and mother, Rose, from Crossmaglen, Co Armagh, now live in Long Island.
"It's very much like a wake, even though we haven't heard any definite word. As every day goes by hope is just dwindling," Ms Traynor said.
Among the 300 missing firemen, many of Irish descent, are Mr Jimmy Gray (34). Mr Gray,whose father emigrated from Kilkenny to the US in 1957, was a fireman in Lower Manhattan. A father of two, Mr Gray's unit was responsible for search and rescue and was one of the first to arrive at the scene. The fireman's grandfather, Pat Gray, lives in Kilkenny and his wife's parents are from Dublin.
Also missing is fireman Timothy McSweeney (37), whose mother came from Dundalk. His aunt, Mairead Kelly, lives in Dundalk, Co Louth, where Mr McSweeney was well known, having visited many times.
Members of the Dundalk and Drogheda Fire Service brought a signed photograph with a dedication to the US Embassy to be passed on to Mr McSweeney's unit in New York.
Investigators in New York have asked the families of people still missing to bring personal items such as toothbrushes and hairbrushes that may contain DNA to help identify bodies found in the wreckage.
In many cases, rescuers are finding only parts of bodies, making it impossible to identify them without the help of DNA evidence.