SOFIA, Bulgaria (AP) -- Bulgarian investigators on Friday staged a re-enactment of the bus bombing that killed five Israeli tourists, the bus driver and the alleged perpetrator at the Burgas airport in July.
The Europol-sponsored experiment, aimed to provide more details about the attack, was done at a police compound near the city of Ihtiman, 40 kilometers (25 miles) east of Sofia. Officials said the results confirmed the facts they had previously established.
In February, an official Bulgarian report said investigators had "well-grounded reasons" to suggest that two men suspected in the attack belonged to the militant wing of the Shiite Islamist group Hezbollah.
Iran is said to be a backer of Hezbollah, and Israel has accused Iran of involvement in the bombing. Bulgarian investigators said they have found no evidence tying Iran to the July 18, 2012, attack.
Georgi Iliev, head of the team of investigators, said that at this stage the investigation cannot say who is behind this act.
"We can answer this question only after the perpetrators of this terror act are caught," Iliev told the Associated Press.
Three men are suspected in the attack including the dead bomber, whose identity has not been established. The names of the two other suspects, believed to still be alive, have not been released to the public.
On Friday, two buses were positioned in the same way as they were at the Burgas airport, while the bomb was a copy of the one that exploded, Iliev said.
Dummies, made of jelly material with silicone-based collagen to correspond to human muscle and bone density, were placed inside and around the buses to match to security camera images and witness accounts, Iliev said.
Smoke billowed from the bus after the bomb exploded on Friday. It was activated remotely, as investigators believe had been done in the attack.
Parts of the bus and of the dummies were ripped apart and could be seen as far as 100 meters away from the bus.
The dummy of the alleged bomber with nearly 3 kilograms (6.6 pounds) of explosives in his backpack was placed half a meter from the luggage compartment with his back toward the bus.
After the blast, the head of the dummy was found 40 centimeters (16 inches) from the spot where the head of the bomber in Burgas had been found, said Boyko Naydenov, director of the National Investigating Service.
"The results are more than satisfying. All facts that we had established during the investigation so far, were confirmed by this explosion," Naydenov said but refused to elaborate.
"Do not expect us to reveal details of the investigation before we are finished and have filed an official indictment in court," he said, adding that charges against the perpetrators will be pressed "soon."
Bulgarian officials have said that the surviving two people involved in the attack were holders of Canadian and Australian passports.
The identity of the bomber remains unknown. Samples of his DNA have been shared with foreign intelligence agencies without finding a match.
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