As relatives began arriving at the Russian Black Sea resort of Sochi, to identify bodies recovered from Thursday's crash of a Siberian Airlines flight, there was growing acknowledgement that the tragedy was probably caused by a Ukrainian missile. However, investigators had still not ruled out terrorism.
All 78 passengers and crew were killed in the crash, which took place two hours after the plane had taken off from Tel Aviv for the Siberian city of Novosibirsk; most of the passengers were Russian-born immigrants to Israel en route to visit their families.
Pentagon officials, citing satellite photography, are adamant that "every indication" points to the Tupolev-154 having been struck by a missile fired during Ukrainian military exercises. And the Ukrainian Prime Minister, Mr Anatoly Kinakh, has conceded that this theory has "a right to exist," although his spokesman stressed that it was "too early to draw any conclusions."
The Ukrainian defence authorities have been insisting that the manoeuvres, during which they acknowledge that live missiles were fired at unmanned aircraft, were too far from the aircraft's flight path to have been a factor. The Ukrainian Defence Minister, Mr Alexander Kuzmuk, claimed that all data from the exercises had been rechecked, that all missiles had been accounted for and that none had "gone in the direction" of the airliner.
Some Ukrainian analysts point out that their defence establishment initially issued similarly strenuous denials of responsibility 18 months ago, when a missile flew off course and killed four residents in an apartment block north of Kiev.
Missile experts also rejected Ukrainian assertions that the S-200 and S-300 ground-to-air missiles used in Thursday's exercises did not have the range to reach the plane, which may have been up to 200 miles away. Some versions of these missiles do indeed have that kind of range, the experts said, and they are designed precisely to target aircraft.
At the same time, however, the official Russian inquiry into the disaster has been instructed to take terrorism into account as a prime possible cause, and initial evidence from the crash scene was seen by some sources yesterday as bolstering that theory. The black box flight recorders have not been recovered, but what is believed to be the cockpit door has been pulled from the sea and found to contain several small holes that might have been made by bullets. A spokesman for the Russian State Co-ordinating Rescue Centre said no firm conclusions had been drawn at this stage.
An Israeli rescue team is to go to the scene day, and Russia and Israel have agreed to "full co-operation" in investigating the disaster. Israel has ruled out any security breach at Tel Aviv's Ben-Gurion Airport.
Another possible cause is a technical malfunction. Three Tupolev-154s have crashed since 1994, with the deaths of more than 300 people. And Israel's Airports Authority is on record as warning of an imminent air disaster because of "flawed maintenance" by airlines based in the former Soviet Union.
The rabbi of Novosibirsk said that the entire community was "in shock".
Relatives are being offered psychological counselling, and Israel is paying for them to fly to the disaster scene.