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.

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.

A Bulgarian government plane will fly some 100 Israelis who were not wounded and wanted to cut short their vacation back to Israel.