The Brazilian Defence Minister has said he has no doubt that wreckage spotted in the Atlantic today by a military aircraft is from the missing Air France jet.
A naval vessel is expected to reach the area more than 600km off the northeast coast of Brazil tomorrow.
Earlier, Aer Lingus confirmed that two of its employees were on the plane, which vanished over the Atlantic while on a flight to Paris from Brazil .
They are believed to be from Eastern Europe and were based at the airline's headquarters in Dublin.
Aer Lingus says 'it is working closely with Air France, the French authorities and the respective embassies of the two staff members at this difficult time.'
The jet, carrying 228 people, disappeared after apparently encountering turbulence.
Three Irish doctors were among the passengers on the plane.
The three have been named as Aisling Butler, from Roscrea, Co Tipperary, Jane Deasy from Rathgar in Dublin and Eithne Walls, from Ballygowan, Co Down.
They were returning home after a holiday in Brazil and had all graduated in medicine from Trinity College Dublin two years ago.
The Department of Foreign Affairs has been in touch with the families and has offered assistance.
French President Nicolas Sarkozy told relatives gathered at Charles de Gaulle Airport last night that there was little hope of finding survivors.
Speculation is focusing on the possibility that the aircraft flew into a violent storm early yesterday, four hours into its 11-hour flight.
The pilot was experienced and the Airbus 330 has an excellent safety record.
The search for the missing aircraft is continuing in the Atlantic with ships and aircraft from Brazil, France, Spain and the US involved.
The search area is reported to have been narrowed down to a few square nautical miles.
Pilots flying a commercial jet from Paris to Rio de Janeiro for Brazil's largest airline, TAM, said they saw what they thought was fire in the ocean along the Air France plane's route early yesterday.
Brazilian Air Force spokesman Col Jorge Amaral said authorities were investigating the report.
Father's grief for missing daughter
Aisling Butler's father John said he could not describe his family's grief.
'We know Aisling is gone, we are sure of that,' he said. 'It is just about trying to live now, I have to live for my wife and my only other daughter Lorna.'
When he heard about the missing plane he initially thought Aisling's flight was due in the following day but decided to check the travel details in his deleted emails.
'When I opened it up a nightmare opened up as well,' he said.
Mr Butler said his daughter, who celebrated her 26th birthday just over two weeks ago, lived for her job as a young doctor but also enjoyed life to the full.
She was doing an internship in Tallaght Hospital in Dublin and was due to move to St James's Hospital next month.
Staff at Tallaght Hospital will hold a special service today for all on Flight 447.
Eithne Walls is a former member of the Riverdance troupe, having joined in 1998 aged 18.
Julian Erskine, executive producer of Riverdance, described her as 'bright and sparkling' and someone who made an impact on everyone she met.
Ms Walls works in the Royal Victoria Eye and Ear Hospital in Dublin.
The young women had gone on a two-week holiday to Brazil to visit other college friends who were travelling on to Australia.
President Mary McAleese said she was thinking about the families of the missing passengers.
'My thoughts and prayers, and the thoughts of everyone, are with the Irish families and the families of everyone on board at this very difficult time,' she said.
Irish embassies in both France and Brazil are keeping in close contact with the investigators.
All 228 people on board the airliner, including a baby and seven children, are feared dead.
The passenger list also includes 61 French and 58 Brazilians among the 32 nationalities on board.
Taoiseach Brian Cowen said the Government was deeply concerned and wanted to express its solidarity with families who are anxiously waiting for news of loved ones.
'Our primary concern is for the families during this difficult time,' he said.
'The Government is offering support to the families as they wait for news of their loved ones.'
