Russian recovery crews skimmed bodies and wreckage from the Black Sea on Friday, seeking clues to what caused a passenger jet to explode without warning and plummet into the water, killing all 78 people on board.
Russian officials appeared to favor terrorism as an explanation but did not rule out that a Ukrainian surface-to-air missile might have gone astray Thursday during military exercises, shooting down the Siberian Airlines charter flight.
"[We] are investigating all scenarios for the accident--absolutely all scenarios," said Russian Defense Minister Sergei B. Ivanov. He said the Kremlin had sent an "urgent inquiry" to the Pentagon seeking "any evidence they can provide that might shed light on this incident."
The joint Russian-Ukrainian investigation is led by Vladimir B. Rushailo, chairman of Russia's powerful Security Council. He said remains of the aircraft were spread over a 7-square-mile area where the sea is nearly 7,000 feet deep. Any debris not floating on the surface, including the plane's flight data and cockpit voice recorders, will be virtually irretrievable, he said.
"Our job today is to collect everything we can from the water's surface," he told a news conference in the Black Sea resort city of Sochi, about 120 miles from the crash site. "We need to do this because of currents in the area, and if we do not deal with this problem now, many parts can be lost."
Rushailo said he had sent inquiries to a number of countries, including the United States, that might have expertise in retrieving objects from such depths.
In addition, the Russian prosecutor general's office opened a criminal investigation into the crash as a possible act of terrorism.
"The terrorism theory remains central, although all the other versions, many of which have already been mentioned by the mass media, will be checked most thoroughly," the prosecutor general's office said in a statement.
At the crash scene, recovery workers pulled several large pieces of the fuselage from the water, including a section of the cockpit.
"By the time we arrived, there were no solid parts of the plane on the surface," Anton Lebedev, co-pilot of the first rescue helicopter to reach the site, said by telephone from Sochi. "As for the plane debris, it was mostly parts of the plane's upholstery made of plastic. We also spotted some personal belongings--suitcases torn open, articles of clothing and other debris that did not sink."
Lebedev said his crew spotted an approximately 15-foot-long, dun-colored cylinder that looked like part of a missile casing. U.S. intelligence officials have said they believe a 35-foot-long S-200 missile may have downed the plane. The S-200 missile has four 16-foot-long boosters attached to its sides.
"It was impossible to tell whether [the fragment] was originally part of the plane or the remnants of a missile or something else," Lebedev said. "The object is still floating very close to the crash site, where the rescue ships are, and sooner or later it will be retrieved from the water."
In addition, several recovery workers reported seeing bullet-like holes in sections of the fuselage. Both S-200 and S-300 missiles--two types of long-range surface-to-air missiles tested during the exercises--typically detonate before hitting the target and spray it with metal fragments.
Rushailo tried to quash speculation about the alleged holes, saying the cause of the crash will be determined only by a thorough investigation.
"If we are talking about bullet holes, only a ballistics expert can make such a determination because this kind of accident can cause a variety of damage, including round holes," he said.
Ukraine Denies Missile Could Have Hit Plane
Ukrainian military officials continued to maintain that the disaster could not have been caused by an errant missile.
Igor Khalyavinsky, deputy head of the Defense Ministry media department, said 23 missiles were launched during joint Russian-Ukrainian exercises at the Opuk naval firing range, more than 200 miles from the crash site. All the targets were no more than 25 miles from their launch sites, he said, and the launches were monitored from 22 stations.
"The data received by both the Ukrainian and the Russian sides coincides completely," Khalyavinsky said. "All 23 launched missiles reached their designated targets, whose coordinates do not coincide with those of the plane."
However, independent military analyst Alexander I. Zhilin, a retired Russian air force colonel, said a missile theoretically could go astray after reaching its target.
"It is quite possible that the Ukrainian air defense forces may have stopped following a missile once it reached its designated destination and may have mistaken a possible explosion of the missile which followed its contact with the plane for the self-destruction of the missile," Zhilin said. "It is also possible that upon reaching its destination, a missile could have picked up a strong signal--from the plane, for instance--and could have deviated from its original course."
In addition, Zhilin said he doubted that the Ukrainian military could track a missile along the more than 200 miles to the site where the plane exploded.
Most Passengers Visiting Relatives for Holiday
"The problem here is that the Ukrainian armed forces are in such a terrible condition that they do not even follow their own fighter planes in the air, to say nothing about monitoring a missile's trajectory after it reaches its destination," he said.
The charter flight was en route from Tel Aviv to the Siberian city of Novosibirsk when it exploded above 30,000 feet. Most of the passengers were naturalized Israelis of Russian origin traveling to visit their families during the Jewish holiday of Sukkot.
Siberian Airlines raised the death toll by two on Friday to 78; 66 were passengers and 12 were crew members. Two of the passengers were small children, each traveling on a parent's ticket, airline officials said.
The airline provided a special plane to bring relatives of the victims to Sochi for the grim process of claiming the remains.
"As far as I know, they've retrieved 13 bodies," said Valery Chakhovsky, trying hard to contain his emotions as he spoke with television reporters. "Please forgive me. My wife is dead." Then, as if to preserve her memory, he pronounced her name with traditional Russian formality--"Galina Nikolayevna"--before hurriedly turning away.
The bodies were pulled from the water before stormy weather forced a halt in salvage efforts. Rescue workers said they expected most of the rest of the bodies would not be recovered.
Alexei Kuznetsov and Yakov Ryzhak of The Times' Moscow Bureau contributed to this report.