President Mary McAleese and Canadian Prime Minister Mr Paul Martin joined victims' families at a commemoration in west Cork this morning to mark the 20th anniversary of the Air India atrocity.
More than 200 relatives of the 307 passengers and 22 crew who died in the tragedy attended the ceremony, which started at 8am.
The ceremony was timed to coincide with the time that the bomb planted by Sikh extremists exploded at 8.13am on June 23rd, 1985, as the aircraft was en route from Vancouver and Montreal to New Delhi via London.
Addressing the commemoration President McAleese described the tragedy as "a wicked event which is without parallel in Irish aviation history."
She went on to express sympathy with those who had lost loved ones and said: "We Irish feel a particular affinity with those who perished, so many of them Indian emigrants living in Canada who were returning on holiday to the land of their birth. We Irish have a long emigrant history and we know how important such a visit is in the lives of the emigrant and their families at home."
White balloons representing the 329 who died and two baggage handlers who were killed in another Sikh extremist explosion at Toyko's Narita airport on the same day were released, and 331 white lamps were set afloat at sea.
Wreaths were laid, and addresses were also given by Mr Martin, and representatives of the families of those who died.
One hundred and thirty-one bodies were recovered 100 miles off Cork and brought to Cork University Hospital. The hospital held an ecumenical memorial service yesterday.