GRABOVO, Ukraine - A Malaysia Airlines Boeing 777 with 298 people aboard exploded, crashed and burned on a flowered wheat field Thursday in a part of eastern Ukraine controlled by pro-Russia separatists, blown out of the sky at 33,000 feet by what Ukrainian and U.S. officials described as a Russian-made anti-aircraft missile.
Ukraine accused the separatists of carrying out what it called a terrorist attack.
U.S. intelligence and military officials said the plane had been destroyed by a Russian SA-series missile, based on surveillance satellite data that showed the final trajectory and impact of the missile but not its point of origin.
There were strong indications that those responsible may have errantly downed what they had thought was a military aircraft only to discover, to their shock, that they had struck a civilian airliner. Everyone aboard was killed, their corpses littered among wreckage that smoldered late into the summer night.
Russia's president, Vladimir V. Putin, blamed Ukraine's government for creating what he called the conditions for the insurgency in eastern Ukraine, where separatists have bragged about shooting down at least three Ukrainian military aircraft. But Putin did not specifically deny that a Russian-made weapon had felled the Malaysian jetliner.
Whatever the cause, the news of the crashed plane, with a passenger manifest that spanned at least nine countries, elevated the insurgency into a new international crisis. The day before, the U.S. had slapped new sanctions on Russia for its support of the pro-Kremlin insurgency that has brought East-West relations to their lowest point in many years.
Making the crash even more of a shock, it was the second time within months that Malaysia Airlines had suffered a mass-casualty flight disaster with international intrigue - and with the same model plane, a Boeing 777-200ER.
The government of Malaysia's prime minister, Najib Razak, is still reeling from the unexplained disappearance of Flight 370 in March, somewhere over the Indian Ocean. He said he was stupefied at the news of Flight 17, which had been bound for Kuala Lumpur, the Malaysian capital, from Amsterdam with 283 passengers, including three infants, and 15 crew members.
Aviation officials said the aircraft had been traveling an approved and heavily trafficked route over eastern Ukraine, about 20 miles from the Russia border, when it vanished from radar screens at 2:15 p.m. local time, with no distress signal.
"This is a tragic day in what has already been a tragic year for Malaysia," Najib told reporters in a televised statement from Kuala Lumpur. "If it transpires that the plane was indeed shot down, we insist that the perpetrators must swiftly be brought to justice."
Najib said he had spoken with the leaders of Ukraine and the Netherlands, who promised their cooperation. He also said that he had spoken with President Barack Obama, and that "he and I both agreed that the investigation must not be hindered in any way." The remark pointed to concerns about evidence tampering at the crash site, which is in an area controlled by pro-Russia insurgents.
Obama and Putin also spoke about the disaster and the broader Ukraine crisis, White House officials said, and Putin expressed his condolences to Malaysia. But in a statement quoted by Russia's RIA Novosti news agency, Putin said, "This tragedy would not have happened if there was peace in the country, if military operations had not resumed in the southeast of Ukraine."
The United Nations Security Council scheduled a meeting on the Ukraine crisis for Friday morning.
Adding to Ukrainian and Western suspicions that pro-Russia separatists were culpable, Ukraine's intelligence agency, the State Security Service, known as the SBU, released audio from what it said was from intercepted phone calls between separatist rebels and Russian military intelligence officers on Thursday. In the audio, the separatists appeared to acknowledge shooting down a civilian plane.
The Ukrainian Foreign Ministry sent reporters a link to the edited audio of the calls, with English subtitles, posted on YouTube by the SBU.
According to a translation of the Russian audio by the English-language Kyiv Post, the recording begins with a separatist commander, identified as Igor Bezler, telling a Russian military intelligence official, "We have just shot down a plane."
In another call, a man who seems to be at the scene of the crash says that a group of Cossack militiamen shot down the plane. He adds that it was a passenger plane and that the debris contains no sign of military equipment. Asked if there are any weapons, he says: "Absolutely nothing. Civilian items, medical equipment, towels, toilet paper."
Asked if there are any documents among the debris, the man says, "Yes, of one Indonesian student."
Myroslava Petsa, a Ukrainian journalist in Kiev, said that the voices in the audio sounded shocked by what they found in the wreckage.
By Thursday night, U.S. intelligence analysts were increasingly focused on a theory that rebels had used a Russian-made SA-11 surface-to-air missile system to shoot down the aircraft and operated on their own fire-control radar - outside the checks and balances of the national Ukrainian air-defense network - to shoot down the aircraft.
"Everything we have, and it is not much, says separatists," a senior Pentagon official said. "That said, there's still a lot of conjecture."
Russian troops, who have been deployed along the eastern Ukraine border, have similar SA-11 systems, as well as larger weapons known as SA-20s, Pentagon officials said.
Petro O. Poroshenko, Ukraine's president, said he had called the Dutch prime minister, Mark Rutte, to express his condolences and to invite Dutch experts to assist in the investigation.
"I would like to note that we are calling this not an incident, not a catastrophe, but a terrorist act," Poroshenko said.
Reporters arriving at the scene near the town of Grabovo described dozens of lifeless bodies strewn about, many intact, in a field dotted with purple flowers, and remnants of the plane scattered across a road lined with fire engines and emergency vehicles.
"It fell down in pieces," one rescue worker said as tents were set up to gather the dead.
The carcass of the plane was still smoldering, and rescue workers moved through the dark field with flashlights.
For months, eastern Ukraine has been the scene of a violent pro-Russia separatist uprising. Rebels have claimed responsibility for attacking a Ukrainian military jet as it landed in the city of Luhansk on June 14, and for felling an AN-26 transport plane on Monday and an SU-25 jet fighter on Wednesday. But this would be the first commercial airline disaster to result from the hostilities.
Despite the turmoil, the commercial airspace over eastern Ukraine is heavily trafficked and has remained open. Questions are likely to be raised in the coming days about why the traffic line, which is controlled by Ukraine and Russia, was not closed earlier.
With the news of the disaster on Thursday, the Ukrainian authorities declared the eastern part of the country a no-fly zone. U.S. and European carriers rerouted their flights, and Aeroflot, Russia's national carrier, announced that it had suspended all flights to Ukraine for at least three days. The conspicuous exception was Aeroflot flights to Crimea, the southern peninsula annexed by Russia in March, a pivotal point in the Ukraine crisis.
It was unclear late Thursday whether any Americans had been aboard the flight. Russia's Interfax news agency said there had been no Russians aboard.
In Amsterdam, a Malaysia Airlines official, Huib Gorter, said the plane had carried 154 Dutch passengers; 45 Malaysians, including the crew; 27 Australians; 12 Indonesians; nine Britons; four Germans; four Belgians; three Filipinos; and one Canadian. The rest of the passengers had not been identified.
Andrei Purgin, deputy prime minister of the Donetsk People's Republic, an insurgent group in eastern Ukraine, denied in a telephone interview that the rebels had anything to do with the loss of the jet. He said that the rebels had shot down Ukrainian planes before but that their anti-aircraft weapons could reach only to around 4,000 meters, far below the cruising level of passenger jets.
"We don't have the technical ability to hit a plane at that height," Purgin said. He also did not rule out the possibility that Ukrainian forces themselves had shot down the plane.
"Remember the Black Sea plane disaster," he said, referring to the 2001 crash of a Siberia Airlines passenger jet bound for Novosibirsk from Tel Aviv that the Ukrainians shot down by accident during a military training exercise.
In comments broadcast on Ukrainian television, Vitali Klitschko, the mayor of Kiev and a former heavyweight boxing champion, said the crash illustrated the risks to peace in Europe of the fighting in eastern Ukraine.
"This is not just a local conflict in Donetsk and Luhansk but a full-scale war in the center of Europe," he said. "I'm certain the international community this time will pay attention and understand."