Jerusalem (AsiaNews/Agencies) - The man who carried out the attack was of Middle Eastern appearance and probably did not act alone. For Israel and the United States, he belonged to a Hizbollah cell. The identity of the bomber, whether he acted alone or with accomplices, and for what group are questions in search for an answer and are shaping the ongoing investigation into the bus attack in Burgas, Bulgaria, that left seven people dead, including five Israeli tourists, and 32 wounded.

For now investigators are trying to identify possible suspects, sifting through the evidence. The long-haired man wearing a baseball cap seen on CCTV cameras in the lobby of a Black Sea resort (pictured) probably wore a wig and came from the Middle East.

"He had an almost shaven head. . . . His hair was brown," said Afrodita Petrova, from the car rental company where he tried to get a car. He was of Arabic appearance, she added, and had dark skin and spoke English with an Arabic accent. He also had a lot of money in EUR 500 notes. When he tried to hire a car, he was turned down because of doubts about his driving licence photo.

Bulgarian investigators are working with the FBI and the CIA to identify the man through fingerprints and DNA samples.

Bulgaria's State Agency for National Security (DANS) denied media reports suggesting that an active terror cell on Bulgarian soil assisted the Burgas terrorist who "most probably relied on the support of assistants and the logistics of the bomb plot was handled by one or two people who entered and left the country repeatedly".

Bulgarian Interior Minister Tsvetan Tsvetanov said that the suicide bomber used three kilograms of trinitrotoluene explosives (TNT).

As for who was behind the attack, Israel blamed Iran and Hizbollah right after the blast. Now US Department of Defence spokesman George Little said that the attack bore "some of the hallmarks of Hezbollah;" however, the Pentagon was "not in a position to make any final determination".