Radical Shiite group Hezbollah has allegedly denied responsibility for the terror attack on Israeli tourists on Bulgarian soil on Wednesday.

A Hezbollah representative has described the allegation that the group was involved in the attack as "laughable," pointing out that the group "does not wage a war on tourists," Interfax reports, citing Annashra.

Israeli Defense Minister Ehud Barak said the attack was probably initiated by a group under the auspices of "either Iran or other radical Muslim groups," and named Hezbollah and Hamas as likely suspects.

At least 6 Israeli tourists were killed and some 33 were wounded in the explosion which hit their bus at the Sarafovo Airport near Bulgaria's Black Sea city of Burgas at about 5:30 pm EET.

The Bulgarian Interior Ministry said the blast was a terror attack.