The site of the Malaysia Airlines plane crash near the village of Grabovo, Ukraine, on Thursday.Associated Press
Malaysia Airlines 3786.KU -2.17% plane carrying at least 280 passengers and 15 crew crashed Thursday in the battle-torn east Ukraine region of Donetsk, where U.S. intelligence agencies say it was struck by a ground-to-air missile.
The U.S. agencies are divided over whether the missile was launched by the Russian military or by pro-Russia separatist rebels, who officials say lack the expertise on their own to bring down a commercial airline in midflight.
"All roads lead to the Russians to some degree," said a U.S. official.
Russian President Vladimir Putin, in comments carried on the Kremlin website, said, "This tragedy wouldn't have happened if there had been peace on this territory, if the military actions hadn't been restarted in southeast Ukraine."
The disaster comes as a new trauma for Malaysia Airlines, the carrier already at the center of a global mystery over the disappearance in March of one of its flights, another Boeing BA -1.21% 777 that went missing en route from Kuala Lumpur to Beijing.
The airline said contact was lost with Flight 17 about 50 kilometers (30 miles) from the Russia-Ukraine border. The Boeing 777 left Amsterdam around noon on Thursday and was due to arrive in Kuala Lumpur early Friday.
The plane went down near the separatist-controlled village of Hrabove in an area that has witnessed heavy fighting in recent days.
President Barack Obama called the crash "a terrible tragedy" and told Ukraine President Petro Poroshenko that all evidence at the crash site must "remain in place."
Separatists immediately sent their personnel to the scene after the crash, which Ukrainian authorities complained they were unable to reach.
Konstantin Knyrik, a spokesman for a separatist group called the South East Front, told the Interfax news agency the rebels had located the Boeing 777's black boxes at the crash site. He said rebel-friendly law enforcement officials from the Donetsk region were working on the matter. "They will engage in documentation and investigation of the incident," he told Interfax.
Serhiy Taruta, the tycoon that Kiev authorities appointed governor of the Donetsk region, said separatists were preventing Ukrainian law enforcement and rescue authorities from accessing the crash site.
"This may seriously affect the course of the investigation and the explanation of the true reasons for this tragedy and its scope," he said.
Footage captured by locals from the wreckage site showed a massive gray plume of smoke emerging from a field before sunset. Later images pictured emergency forces hosing down the wreckage, as well as passports, tickets and pieces of bodies found near the crash site.
At the airport in the Malaysian capital, family members expressed frustration over the lack of information and grief over their likely losses. Akmar Mohd Noor said her sister was aboard Flight 17 to join her family for the end of Ramadan celebrations. "She was coming back from Geneva to celebrate with us for the first time in 30 years," she said through tears.
Malaysian Prime Minister Najib Razak said Flight 17 was not flying in restricted airspace, and that it sent no distress call before crashing.
"If it transpires that the plane was indeed shot down, we insist that the perpetrators must swiftly be brought to justice," the prime minister said in Kuala Lumpur.
Mr. Poroshenko expressed condolences to the relatives of those killed and said Ukrainian authorities were engaging in all possible rescue efforts.
In 2001, the Ukrainian military mistakenly shot down a commercial passenger jet that was en route from Tel Aviv to Novosibirsk with a land-to-air missile that was fired during a military exercise. All the 66 passengers and 12 crew members on board the plane were killed in the blast.
For months, Ukrainian forces have been trying to subdue pro-Russia separatists who seized towns across the eastern region in April and declared an independent republic. The fighting escalated this week when Ukrainian authorities reported that one of their military cargo planes and one of their military fighter jets had been downed in the area.
The crash prompted an immediate war of accusations. In a phone call with The Wall Street Journal, Anton Gerashchenko, an adviser to Ukraine's Interior Ministry, alleged that pro-Russia rebels had set up a ground-to-air missile battery near the Russian border by the town of Snizhne.
"They clearly thought that it was a military transport plane that they were shooting at," he said. "They were the ones who did this." His claims couldn't be verified.
In a Facebook post, Mr. Gerashchenko alleged that the separatists had obtained a Buk ground-to-air missile system that locals had seen being paraded near the towns of Snizhne and Torez during the day on Thursday. He said a convoy with the anti-aircraft missile was seen heading toward Shakhtarsk, a town not far from the crash site, about an hour before the plane went down late Thursday afternoon.
In late June, separatist leaders told the Russian news outlets RIA Novosti and Interfax that they had taken control of a Ukrainian air-defense base near the village of Oleksiivka equipped with Buk missiles. The Donetsk People's Republic also posted a photo of the missiles, sometimes known as Gadfly systems, on its official Twitter feed at the time, declaring a victory in having seized the weaponry. The Russian maker of the Buk system, Almaz-Antey, is among the firms the U.S. subjected to new sanctions this week.
Malaysia Airlines Flight 17 crashed in Eastern Ukraine, sparking international speculation that the plane was shot down. Watch some of the latest footage.
WSJ's Jason Bellini walks through the timeline of the tragedy.
U.S. State Department spokeswoman Jen Psaki holds a news conference on what the agency knows about Malaysian Airlines Flight 17, which crashed in the eastern Ukrainian region of Donetsk while carrying 295 people. Photo: Getty Images.
On Thursday, separatist leaders denied they had ground-to-air missiles, such as the Buk system, that were powerful enough to shoot down a Boeing 777 flying at such a height.
"The plane was shot down by the Ukrainian side," Sergei Kavtaradze, one of the leaders of the separatist Donetsk People's Republic, told the Interfax news agency. "We simply don't have those kind of air-defense systems."
Ukraine's president and prime minister didn't immediately assign blame for the incident.
Prime Minister Arseniy Yatsenyuk ordered a special investigation into the crash, as well as into the downing of a Ukrainian AN-26 military cargo aircraft and a Ukrainian SU-25 fighter jet in the same area earlier this week.
"This is the third tragic incident in recent days after the AN-26 and SU-25 were shot down," said Mr. Poroshenko, the president. "We can't rule out that this plane was also shot down, but we underscore that the Ukrainian armed forces were not carrying out any actions to strike airborne targets."
If a passenger jet was shot down over Ukraine, attackers would have had to use a sophisticated surface-to-air missile system, not the shoulder-fired weapons that the separatists say they possess and are easier to use.
Those weapons, nicknamed manpads, have been used in attacks against commercial aircraft in the past. But their range doesn't approach the 30,000-foot cruising altitude of passenger jets.
European flight control agency Eurocontrol said Ukraine had advised pilots on Monday not to fly over the conflict zone in eastern Ukraine at altitudes below 32,000 feet. Flight data from tracking company FlightAware indicated that Flight 17 was flying at 33,000 feet before it came down.
Under a code-share agreement between Malaysia Air and the Dutch airline KLM, the downed flight was also flying as Flight KL4103. Huib Gorter, vice president of Malaysia Airlines, said the plane carried 154 Dutch citizens, 27 Australians, 23 Malaysians, 11 Indians, 6 Britons, 4 Germans, 3 Filipinos, and one Canadian. The nationality of 47 passengers, including any Americans, had not been confirmed, he said. French Foreign Minister Laurent Fabius said at least four French citizens were on board.
Relatives of passengers gathered late Thursday at a restaurant in Amsterdam's Schiphol Airport to be briefed by officials. They were escorted by security officers and couldn't be approached to comment.
Air FranceAF.FR -1.45% KLM, LufthansaLHA.XE -2.37% Malaysia Airlines and Air India announced that they would no longer route planes over the contested regions of eastern Ukraine. The FAA said U.S. airlines had also agreed to avoid the area.
—Jason Ng, Robin Van Daalen, Robert Wall,
Julian E. Barnes and Andrey Ostroukh contributed to this article.