"Israel will locate and act against terror all over the world," Israeli President Shimon Peres said Thursday in a strong response to a suicide bombing against Israeli tourists in Bulgaria a day earlier.

Five Israelis were killed, along with the Bulgarian bus driver, at the Burgas airport when an as-yet unidentified man detonated a powerful charge that ripped through a tour bus full of just- arrived Israeli tourists.

More than three dozen people, mostly Israeli, were wounded, several of them critically. Israeli and Bulgarian government aircraft on Thursday flew the wounded and deceased back to Tel- Aviv.

"This was a bloody attack against civilians going on vacation," Peres said. "They were attacked for the simple and unacceptable reason that they were Jewish or Israeli."

Saying that Israel was "committed to act," Peres warned of his government's determination to punish those behind the attack, stressing that his country would strike "in every nest where terror operates across the world -- we have the capabilities for it."

Peres specifically mentioned Iran as his country's chief suspect in the attack, charging that the Iranian government " remains the greatest danger to world peace, to the peace of civilian life, to innocent people. It is the duty of all us to bring an end to this unnecessary and unjustified danger. We will act together to ensure the terrorists from Lebanon, Syria and Iran cannot raise their heads."

Meanwhile, Israeli security agencies, together with the U.S. FBI and CIA, are working with Bulgarian security services in probing the attack.

Investigators found on the bomber's body what they said appeared to be a false American passport issued in the state of Michigan.

On Wednesday, Israeli Prime Minister Benjamin Netanyahu said of the blast that "all of the signs lead to Iran."

Defense Minister Ehud Barak told Israel Radio Thursday that Hezbollah was behind the blast.

Both Teheran and the Lebanon-based group, however, strongly denied the allegations, with Iranian officials calling the charge "ridiculous."