Sri Lanka's Tamil Tiger rebels have expressed "regret" over the assassination of former Indian Prime Minister Rajiv Gandhi 15 years ago.
Mr Gandhi was opposition leader at the time of his death
Top rebel negotiator Anton Balasingham told private Indian channel NDTV that Mr Gandhi's killing by a suicide bomber was a "monumental tragedy".
Correspondents say it is the closest the rebels have come to admitting they were responsible for the murder.
India was the first country to ban the Tigers as a result of the killing.
The BBC's Ethirajan Anbarasan says the rebels' expression of regret may be linked to their increased international isolation after recent bans by the European Union and Canada.
He says the rebels feel they need some sort of support from India, which once armed and supported them.
"As far as that event is concerned, I would say it is a great tragedy, a monumental historical tragedy for which we deeply regret," Mr Balasingham said.
"We call upon the government of India and the people of India to be magnanimous, to put the past behind and to approach the ethnic question in a different perspective."
Mr Gandhi was opposition leader at the time of his death in 1991, and was campaigning in the southern state of Tamil Nadu in the run-up to a general election when he was killed.
Mr Balasingham said that at the time of Mr Gandhi's death, a gulf had arisen between the rebels and India.
India sent a peace-keeping force to Sri Lanka to disarm the Tigers but ended up fighting them, and withdrew in 1990.
Mr Balasingham said that he now hoped India would intervene once again in the Sri Lanka dispute, and that the rebels wanted a "new relationship" with Delhi.
"India has been silent for the last 15 years and adopted a detached role," he said, "but now there is... the possibility of war emerging, she cannot keep quiet."
'Philosophy of terror'
But his overtures were met with a firm rebuff from Delhi which ruled out any direct talks with the rebels.
"The people of India cannot forget the dastardly crime committed by the Tamil Tigers or at their behest," India's junior Foreign Minister Anand Sharma - and former aide of Rajiv Gandhi - said.
The suspected bomber (centre) shortly before the attack
"Seeking our forgiveness would be tantamount to endorsing their philosophy of terror, violence and assassination.
"India is for peace, stability and the unity of Sri Lanka and we have been supportive of the peace process and it is very sad it has got derailed," he said.
Indian courts are still seeking Tiger leader Prabhakaran and rebel intelligence chief Pottu Amman for the murder of Rajiv Gandhi.