JERUSALEM //Iran yesterday denied "ridiculous" accusations by the "Zionist regime" that it orchestrated the suicide bus bombing in Bulgaria that killed five young Israeli tourists, declaring it condemns "all terrorist acts".
Unconfirmed media reports from Bulgaria last night said the bomber was a 33-year-old Algerian-Swedish national who spent two years in Guantanamo Bay, suggesting he was a member of Al Qaeda and not an Iranian hitman.
If Iran was involved in Wednesday's attack, which also killed the Bulgarian bus driver, it would mark a dangerous escalation in a dirty war between the two arch-enemies.
It would also be the first successful attempt by Iranian-backed agents to kill Israelis abroad after a string of failed bomb plots targeting Israeli diplomats in Georgia, Thailand and India in February. And it would suggest Iran has shifted its focus to softer targets.
Hitting "unwitting tourists" is much easier than targeting diplomats or officials, said Trita Parsi, a leading Iran analyst in Washington.
Regional tensions are already high over Iran's nuclear programme, which Israel repeatedly has threatened to strike if it is not reined in by western sanctions or the stalled diplomatic efforts by six world powers, led by the United States. Tehran insists its nuclear ambitions are peaceful in nature.
Yesterday, the prime minister, Benjamin Netanyahu, accused Hizbollah - "Iran's leading terrorist proxy" - of carrying out the attack and threatened retaliation.
He provided no evidence to substantiate his allegations and no one has claimed responsibility for the attack.
Global powers must now do everything to prevent Iran from "developing the world's most dangerous weapons", a grim-faced Mr Netanyahu added in a brief statement.
Iran, in turn, accuses Israel of terrorism, blaming it for the assassinations of several of its nuclear scientists in recent years, and has promised to avenge their deaths.
Hizbollah, meanwhile, is still seeking payback for the assassination of its shadowy military chief, Imad Mughniyeh, in Damascus in 2008 for which it blames Mossad, Israel's spy agency.
But chiding Israel for "jumping to conclusions", Bulgaria's foreign minister, Nikolay Mladenov, said it was "wrong" to blame any country or organisation when an investigation had only just started.
The Bulgarian authorities released airport security footage of the suspected bomber - a long-haired Caucasian male in a blue T-shirt, plaid shorts and running shoes. He was carrying a backpack and a fake US driving licence issued in Michigan when he targeted the bus outside the Black Sea resort town of Burgas.
Several Israeli commentators also cautioned against rushing to blame Tehran.
"It's far too early to say conclusively who was behind this attack," said Meir Javedanfar, an Iran specialist at the Interdisciplinary Centre in Herzilya, Israel. "Iran is a credible suspect, but we can't rule out Al Qaeda either."
Others Israeli commentators suggested the attack came at a politically opportune moment for Mr Netanyahu, who may be more sensitive to the demands of his right-wing partners after the centrist Kadima party left his coalition on Tuesday.
Amir Oren, a columnist for Israel's Haaretz newspaper, warned that the Israeli premier could use the Bulgaria attack as a pretext to strike at Iran's nuclear facilities but cautioned that "one expects a little more proof" from a prime minister.
Iran's foreign ministry spokesman, Rahim Mehmanparast, said the Islamic republic was "the biggest victim of terrorism" and condemned "all terrorist acts in the world". Israel was launching "baseless accusations" against other countries to "forget its own terrorist" actions in Lebanon and Palestine and against Iranian nuclear scientists.
Giora Eiland, a retired Israeli army general who served as national security adviser from 2003 to 2006, played down the likelihood of the Bulgaria bombing spilling over into war.
He said: "Any response, whatever it may be will not be in the form of an air force operations, or strike - certainly not in Iran over this matter, nor in Lebanon."