BEIRUT: The official explanation for a bus explosion in Damascus on Thursday has been cast into doubt after expert analysis suggested it was "most unlikely" that the reasons given could have caused such damage.
The explosion took place at a garage south of Damascus, causing significant damage to a bus carrying Iranian pilgrims to Sayeda Zainab mosque, a popular Shiite Muslim pilgrimage site. Reports suggest the bus was empty at the time of the explosion.
A statement from Syrian Interior Minister Said Sammour claimed the blast, which killed 3 bystanders, was an accident caused by a tire bursting due to an excess of pressure.
After analyzing photographs of the scene, a UK based professor who has appeared as an expert witness in similar high profile cases, said the explosion "clearly occurred from within the outer bus envelope," rather than in the vicinity of the bus as Syrian officials claimed.
"If the damage process had indeed been started by an exploding tire, then it is most unlikely that it would have been sufficiently powerful to cause the damage shown," said the expert, who wished to remain anonymous.
The expert said that the only way the damage could have been caused by an exploding tire would be if the fuel tank was located at the source of the damage at the back of the bus and it had disintegrated on impact.
The manufacturer of the chassis - a UK based company called Scania - confirmed the fuel tank in the model pictured is fitted at the front of the vehicle, which makes an exploding fuel tank highly improbable.
The expert concluded: "On the available evidence, the involvement of an explosive device cannot be excluded."
Sammour arrived at the scene on the day of the incident and denied rumours of a terrorist attack.
"It is not a terrorist act at all," he said. "It happened while one of the empty bus's tires was being repaired. An explosion took place as a result of the excessive pressure."
Statements from the Syrian government seemed to contradict accounts from eyewitnesses who recounted a large explosion and six dead. Witnesses also reported windows ten meters from the impact were smashed and debris scattered even further. Police sealed off the area and reporters were banned from reaching the site until it was cleared.
In September last year, a bomb attack killed 17 people and injured 17 more, the incident also took place near the Saydah Zeinab shrine. The perpetrators of the attack were thought to be Sunni militants, possibly from the north of Lebanon.
In February last year Imad Mughniyeh, a leading figure in Lebanon's Hizbollah, was killed in a car bomb in Damascus. Hizbollah blamed Israel for the attack.