There have been conflicting reports on whether the third attacker had intended to detonate the bomb, or whether it had been done remotely. The Associated Press on Tuesday quoted the director of the European police organization Europol, Rob Wainwright, as saying that the explosion had been detonated remotely and that investigators thought the third attacker hadn’t intended to die.

Baird went further.

"We urge the European Union and all partners who have not already done so to list Hezbollah as a terrorist entity and prosecute terrorist acts committed by this inhumane organization to the fullest possible extent," he said, adding that Canada would work with Bulgarian authorities, given the apparent involvement of "a dual national living in Lebanon."

Ashton, the EU’s top foreign and security official, said the EU needed to assess the implications of the investigation but stressed that any decision on adding Hezbollah to the EU list of terrorist organizations would require a unanimous decision by the foreign ministers of the 27 EU countries, whose next scheduled meeting is Feb. 18. Such a move would freeze Hezbollah’s assets and cut off funding.

The bombing was the deadliest attack on Israelis abroad since 2004, when 34 people – including 12 Israelis – were killed in a series of three bombing attacks at hotels in Egypt’s Sinai Peninsula.

Israeli officials said the finding didn’t surprise them. They pointed out that Israel had named Hezbollah and its backers in Iran as the perpetrators immediately after the bombing, adding that the attack had "the fingerprints of Hezbollah all over it from day one."

"It was clear right at the outset that Hezbollah was behind this. Bulgarian intelligence wanted to dig deeper. They came out with solid conclusions about the direct responsibility of Hezbollah, and Iran," one senior Israeli official said.

Tsvetanov made no mention of Iran in his remarks, however.

The senior Israeli official, who spoke only on the condition of anonymity because he hadn’t been authorized to speak publicly, said the bombing was one of many carried out against Israeli targets in countries ranging from Georgia and Azerbaijan to India and Kenya.

"The bottom line is that here we have yet another Hezbollah bombing against civilians, this time on European soil. It’s high time that the EU did something," he said. "For the EU to declare Hezbollah a terrorist organization . . . we consider it an inevitable step."