BRUSSELS (EJP)---International leaders were united in unequivocally condemning a terror attack on a bus of Israeli tourists in Burgas, a Black Sea resort in Bulgaria on Wednesday, as the reported death toll was revised to six.

Five tourists died at the scene while the vehicle's Bulgarian driver died in hospital, officials said.

EU foreign policy chief  Catherine Ashton issued a statement ahead of her official visit to Egypt, in which she said she was “appalled” to hear of the “apparent terrorist attack.

She added that was “deeply shocked by the scenes at Bourgas airport, where what should have been the beginning of a happy holiday ended in murder.”

“The EU utterly condemns all acts of terrorism, wherever they take place. The terrorists who planned and carried out this attack must be brought to justice,” she added.

US Secretary of State Hillary Clinton followed President Barack Obama in condemning the bombing “in the strongest terms”, describing it as a “despicable attack on innocent people”. Republican presidential candidate Mitt Romney, due to visit Israel at the end of this month, called it “a sobering reminder that the scourge of terrorism continues to threaten all free people”.

UN Secretary-General Ban Ki-moon meanwhile issued a statement Wednesday condemning “in the strongest possible terms today’s deadly bombing attack on a bus carrying Israeli tourists”, adding “his condolences to the victims and their families, to the Governments and people of Bulgaria and Israel”.

But UN Watch, a Geneva-based NGO monitoring  UN activities, criticised the wording of Ban’s statement as “weak” in comparison with his reaction to the bombing of churches in Kenya two weeks ago, when he spoke of “reprehensible and criminal” “terror attacks”, and called for the perpetrators to be “held to account”.

The organization called for Ban to clarify his position and apply the internationally-accepted description of terrorism for this latest attack.

UN Watch also highlighted the silence of UN High Commissioner for Human Rights Navi Pillay following the bombing in Bulgaria, emphasising that “by contrast, hours after the Gaza flotilla incident of 2010, Ms. Pillay expressed her “shock” and condemned Israel”.

Further commenting on the failure of the 47-nation UN Human Rights Council itself to comment on the incident, it issued a statement calling “on the High Commissioner to speak out for victims of terrorism, condemn today’s gruesome murders in Bulgaria, and instruct her staff to investigate the perpetrators and hold them fully accountable for the crimes”.

Close Israeli ally Canada was quick to speak out following the attack. Canadian Foreign Minister John Baird said he was “deeply saddened to learn of the deadly terrorist attack”.

“On behalf of all Canadians, I offer our sincere condolences to those who lost loved ones in the deadly explosion. I wish a speedy recovery to those who were injured,” he said, adding that “Canada condemns such heinous acts without reservation and is confident that Bulgarian authorities will do all they can to ensure the perpetrators of this attack are brought to justice”.