Bulgarian officials say a suicide bomber carried out Wednesday's deadly attack on a bus carrying Israeli tourists.

Interior Minister Tsvetan Tsvetanov said Thursday the attack in the Black Sea city of Burgas killed six Israelis along with the Bulgarian driver of the bus.

He said the suspected bomber has not been identified, but was carrying a fake driver's license from the U.S. state of Michigan.

No group claimed responsibility for the blast.

Israeli officials have blamed Iran. Israeli Prime Minister Benjamin Netanyahu said that similar attacks on Israeli tourists in India, Thailand and other places point to Iran. He did not clarify.

U.S. President Barack Obama condemned the bombing as “a barbaric terrorist attack.”