(CBS/AP) SOFIA, Bulgaria - Bulgaria's interior minister says a bombing that killed eight people and injured dozens on a bus full of Israeli tourists was most likely a suicide attack. He says the suspected attacker was carrying a driver's license issued in Michigan, which had been sent to the FBI.
Interior Minister Tsvetan Tsvetanov said Thursday the suspect appeared on security camera tape near the bus for nearly an hour before the attack.
Tsvetanov said the death toll had risen to eight, as the Bulgarian driver of the bus died in the hospital. Six of the victims are Israeli citizens, while the nationality of the suicide bomber remains unknown.
Other reports said the ID found on the suspect's remains was a U.S. passport issued in Michigan, which was determined to be a fake. That report could not be confirmed.
A Bulgarian government plane will fly some 100 Israelis who were not wounded and wanted to cut short their vacation back to Israel.
The bombing was the latest in a series of attacks attributed to Iran that have targeted Israelis and Jews overseas and threatened to escalate a shadow war between the two arch-enemies. Iran has denied involvement in the past but did not comment on Wednesday's attack.
No group immediately claimed responsibility for the attack, but suspicion immediately fell upon Iran and its Lebanese proxy, the Hezbollah guerrilla group.
"All signs point to Iran," Netanyahu said. "Just in the past few months, we have seen attempts by Iran to harm Israelis in Thailand, India, Georgia, Kenya, Cyprus and more. This is an Iranian terror attack that is spreading across the world. Israel will react forcefully to Iran's terror."
The Israeli leader gave no evidence to back his charges.
President Obama termed it a "barbaric terrorist attack" and called Israeli Prime Minister Benjamin Netanyahu to pledge U.S. help in finding the perpetrators.
The blast gutted the bus at the airport in the quiet Black Sea resort city of Burgas, some 250 miles east of the capital, Sofia, where the Israelis had just arrived on a charter flight from Tel Aviv carrying 154 people, including eight children.