SYDNEY: Australia Wednesday said its police had been involved in a probe into a deadly bomb attack on Israeli tourists in Bulgaria which found that one of those involved was an Australian with ties to Hezbollah.

Bulgaria said Tuesday that two people of interest in the July 2012 bomb attack that killed five tourists were Australian and Canadian citizens who had lived in Lebanon and were part of the Shiite armed movement Hezbollah.

"What we can make as a justified conclusion is that the two persons whose identity we have established belonged to the military wing of Hezbollah," Bulgaria's Interior Minister Tsvetan Tsvetanov told reporters.

Australia's Foreign Minister Bob Carr said the Bulgarian government had indicated that one person of interest in the matter may be an Australian passport holder.

"The Australian Federal Police has worked with Bulgarian authorities in pursuit of those responsible for the bombing," he said in a statement.

"The Australian government condemns all acts of political violence and terrorism and welcomes today's evidence of progress in this investigation," he added.

Five Israeli tourists and their Bulgarian driver were killed in a bus bombing at Burgas airport on the Black Sea in July last year, the deadliest attack on Israelis abroad since 2004.

Some 30 Israelis were also wounded in the attack, in which the bomber also perished.

The blaming of the attack on Hezbollah has triggered renewed pressure for the European Union to follow Canada, the United States and others in formally designating the movement a terrorist group.

Carr said Australia had listed the Hezbollah External Security Organisation as a terrorist group since 2003, and support for or membership of the organisation was an offence under Australian law.