Iran said it will recall its ambassador to Sofia and consider downgrading relations with Bulgaria after a criminal investigation accused the Iran-backed Hezbollah of carrying out last year’s bus bombing that killed five Israelis and a Bulgarian near the resort town of Burgas, Bulgarian media reported Sunday.

According to Bulgarian news website 24 Chasa, Iran’s Ambassador Gholamreza Bageri said at a Friday press conference that “Iran is friendly to Bulgaria and there is no reason to change that,” but directed journalists to seek further details and clarifications from Bulgarian authorities.

Bagerei also denied Israeli accusations of Iranian involvement in the July 2012 attack.

Bageri said his country condemns all forms of terrorism and is itself a victim of such attacks. He suggested that there were similarities between the Burgas attack and the 2010 assassination of Hamas leader Mahmoud Mabhouh in Dubai, for which the Israeli Mossad was widely suspected, insofar as both incidents involved assailants in possession of Western passports.

The Bulgarian report made no mention of an Iranian connection to the bombing, despite Israeli expectations.

On Saturday, Foreign Minister Nikolay Mladenov told Bulgarian radio that Sofia cannot formally label Hezbollah a terror organization because it did not have the legal framework for it.

Mladenov said the issue would be discussed at an EU meeting of foreign ministers later this month.

“A lot of details of the findings will be discussed. In the following months and weeks what we found related to the attack will not remain without its consequences on the part of the EU,” Mladenov said, according to the Sofia News Agency.

Investigators say they believe two of the suspects behind the bombing, who hold Canadian and Australian passports, are currently in Lebanon.

Since the probe’s release, Sofia has sent requests for cooperation to Israel, Lebanon, Canada and Australia, AFP reported.

Lebanon has been asked to arrest and question the suspects, Bulgaria’s Standart newspaper reported.

Joshua Davidovich contributed to this report