Germany on Wednesday warned of “consequences” for Hezbollah if allegations that the group was behind an attack that killed five Israeli tourists and their local bus driver in Bulgaria last year are confirmed.

Bulgarian officials said the Lebanese group had been linked to the sophisticated bombing carried out by a terrorist cell that included Canadian and Australian citizens.

“We have well-grounded reasons to suggest that the two were members of the militant wing of Hezbollah,” Bulgarian Interior Minister Tsvetan Tsvetanov said after a meeting of Bulgaria’s National Security Council on Tuesday.

The announcement put pressure on countries such as France and Germany, which haven’t banned Hezbollah despite the urging of Israel and the United States.

Steffen Seibert, a spokesman for Chancellor Angela Merkel, said Wednesday that “Federal Chancellor Angela Merkel last year condemned the attack in Burgas in the strongest terms.”

“Following careful investigations, the Bulgarian authorities now have established a connection of the perpetrators to the military arm of Hezbollah,” Seibert stated. “Should the evidence that Hezbollah, indeed, is responsible for this despicable attack be substantiated, consequences will have to be drawn.”

The foreign policy spokesman of Merkel’s governing center-right party CDU, Philipp Mißfelder, was more explicit in his reaction: “The European Union must act now and use its instruments to classify Hezbollah as a terrorist organization,” he said in a statement Wednesday.

“Terrorist attacks are at the core of the strategy of Hezbollah. Since its founding in 1982, its declared goal is destruction of the state of Israel,” Mißfelder said. “The attack on civilians on the territory of the European Union requires another intense debate over whether Hezbollah should be included on the EU list of terrorist organizations. This would hurt the militia where it is most sensitive, as it would freeze its assets and interrupt its cash flow in Europe. Hezbollah would thus lose its financial basis for further acts of terrorism.”

Including Hezbollah on the EU’s terror list would also give “an unequivocal sign that our liberal societies have no tolerance for those who sow hatred and threaten life and limb of innocent people,” he added.

The Associated Press contributed to this report.