Jeremy Corbyn has admitted attending a wreath-laying ceremony for the terrorists behind the Munich massacre, but denied paying tribute himself.
The Labour leader said he had been "present" at a ceremony where "those who were killed in Paris in 1992" were commemorated. That is understood to be a reference to Atef Bseiso, widely considered to have been involved in masterminding the murder of 11 Israeli athletes at the 1972 Olympics in Munich.
However, Mr Corbyn said had he was there because he wanted to "see a fitting memorial to everyone who had died in every terrorist incident everywhere".
He said he did not "think" he had laid a wreath in memory of the Munich attackers.
The Labour leader had come under mounting pressure to explain why he had attended a memorial event at the Palestinian Martyrs Cemetery in Tunisia in 2014 after pictures showed him holding a wreath next to a memorial plaque for the perpetrators of the Munich attack.
Labour has insisted he had only laid a wreath at another memorial, and did not pay tribute to the Munich terrorists.
Speaking for the first time since the images emerged, Mr Corbyn told Sky News: "A wreath was indeed laid by some of those who attended the conference for those who were killed in Paris in 1992."
Asked whether he was involved in the wreath laying, he said: "I was present when it was laid. I don't think I was actually involved in it."
He added: "I was there because I wanted to see a fitting memorial to everyone who has died in every terrorist incident everywhere, because we have to end it. You cannot pursue peace by a cycle of violence. They only way you pursue peace is by a cycle of dialogue."
Bseiso was the Palestinian Liberation Organisation's (PLO) head of intelligence and is widely believed to have played a key role in planning the attack.
His killing in Paris in 1992 was attributed to Israel, although the country denied involvement and said he had been murdered by a rival PLO faction.
The Munich massacre saw 11 members of the terrorist group "Black September" torture 11 Israeli athletes in their Olympic Village apartment before murdering them.
Labour has insisted Mr Corbyn was only at the cemetery to pay tribute to the 47 Palestinians killed in an Israeli air strike on a PLO base in Tunisia in 1985.
The images published by the Daily Mail show him holding a wreath next to the memorial to the Munich bombers. The paper said the memorial for the victims of the 1985 attack is 15 feet away, in a different part of the cemetery.
Mr Corbyn also made reference a wreath being laid for Bseiso in an article for the Morning Star in 2014.
He wrote: "After wreaths were laid at the graves of those who died on that day and on the graves of others killed by Mossad agents in Paris in 1991, we moved to the poignant statue in the main avenue of the coastal town of Ben Arous, which was festooned with Palestinian and Tunisian flags."
The mention of the 1991 killing is believed to be a mistake and instead refer to the death of Bseiso in 1992.
The widows of two of the athletes murdered in the Munich attack expressed outrage at the photos of Mr Corbyn standing next to Bseio's grave.
Ankie Spitzer and Ilana Romano, whose husbands Andre and Yossef were among 11 athletes murdered, told Jewish News: "We do not recall a visit of Mr Corbyn to the graves of our murdered fathers, sons and husbands.
"They only went to the Olympic Games in order to participate in this festival of love, peace and brotherhood; but they all returned home in coffins.
"For Mr Corbyn to honour these terrorists is the ultimate act of maliciousness, cruelty and stupidity."
And they added: "Do not forget, Mr Corbyn, that you will be judged by the company you keep."
Sajid Javid, the home secretary, said Mr Corbyn should quit over the issue.
He wrote on Twitter: "If this was the leader of any other major political party, he or she would be gone by now."
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