DUBAI/KIEV • Ukraine outlined four potential scenarios yesterday to explain the deadly crash of one of its airliners in Iran, including a missile strike and terrorism, as Iranian investigators said the plane was on fire before it fell to the ground.
Kiev said its investigators wanted to search the site of Wednesday's crash south-west of Teheran for possible debris of a Russian-made missile used by Iran's military.
An initial report by Iran's civil aviation organisation said the plane had experienced an unspecified technical problem.
A collision and an engine explosion are other lines of inquiry.
The Ukrainian International Airlines Boeing 737-800, flying to Kiev and carrying mostly Iranians and Iranian-Canadians, crashed shortly after taking off from Teheran's Imam Khomeini Airport, killing all 176 people on board.
The Iranian report cited witnesses on the ground and in a passing aircraft flying at high altitude as saying the plane was on fire while still aloft.
It said the three-year-old airliner, which had its last scheduled maintenance on Monday, encountered a technical problem shortly after take-off and started to head towards a nearby airport before it crashed.
The report said there was no radio communication from the pilot and that the aircraft disappeared from the radar at 8,000ft (2,440m).
It is so far unclear if any technical issue could be related to a maintenance fault or defective part.
A Canadian security source told Reuters that there was evidence one of the engines had overheated.
The crash happened hours after Iran launched missile attacks on US-led forces in Iraq, leading some to speculate that the plane may have been hit.
The initial assessment of Western intelligence agencies was that the plane had suffered a technical malfunction and had not been brought down by a missile, said five security sources - three Americans, one European and the Canadian - who asked not to be named.
Ukraine Security Council Secretary Oleksiy Danylov said the country's investigators wanted to search the crash site for possible Russian missile debris after seeing information on the Internet.
He referred to an unverified image circulated on Iranian social media purportedly showing the debris of a Russian-made Tor-M1 surface-to-air missile of the kind used by the Iranian military.
The United States, as the country where the plane was designed and built, would usually be allowed to be accredited but neither side has said whether US investigators will be dispatched to Iran.
Iran's aviation body could not be reached for comment to clarify its position.
The Ukrainian airliner took off at 6:12am local time and was given permission to climb to 26,000ft, the report said. It crashed six minutes later near the town of Sabashahr.
Bodies and body parts recovered from the site of the crash have been taken to the coroner's office for identification, the Iranian report said.
In the absence of direct flights, the Teheran-Toronto route, with a stop in Kiev, was popular with Canadians of Iranian descent visiting Iran.