A Malaysian airliner with 295 people on board has crashed in Ukraine on a flight from Amsterdam to Kuala Lumpur, amid allegations it was shot down.
Dozens of bodies are scattered around what is believed to be the wreckage of the jet near the village of Grabovo, a Reuters correspondent reports. Flight MH17 had been due to enter Russian airspace when contact was lost.
Both the Ukrainian government and rebels have denied shooting it down in the region close to the Russian border.
Russian separatists are believed to have shot down two Ukrainian military planes over the region in recent days.
The pro-Russian rebels have been fighting government forces in the region.
Analysis: Jonathan Beale, BBC News
A defence expert has told the BBC that shooting down a plane at 10,000m (32,000ft) would have required a long- range surface-to-air missile – possibly guided by radar.
That suggests it is unlikely it could have been downed by a portable air defence missile, or Manpad, which has a much shorter range.
The only other possibility is for an aircraft at that height to be downed by a fighter carrying air-to-air missiles.
The US will have access to satellite imagery that should be able to identify ultra-violet plumes if a long-range surface-to-air missile was fired.
Ukraine has accused Russia’s military of supplying advanced missiles to the rebels.
Malaysia’s Prime Minister Najib Razak reportedly said he was launching an immediate inquiry into the crash.
Russian President Vladimir Putin spoke to his US counterpart, Barack Obama, by phone about the crash, the Kremlin said in a statement (in Russian).
“The Russian leader informed the US president about an air-traffic controllers’ report that came just before their phone conversation that a Malaysian plane crashed in Ukraine,” the statement said.
The plane fell between Krasni Luch in Luhansk region and Shakhtarsk in the neighbouring region of Donetsk.
Anton Herashchenko, an adviser to Ukraine’s interior minister, was quoted by the Associated Press as saying the plane had been hit by a missile at an altitude of 10,000m (33,000ft). The claim could not be verified independently.
Earlier on Thursday, Ukrainian officials blamed the Russian air force for shooting down one of its ground attack jets on Wednesday.
Confirming the crash, Ukrainian President Petro Poroshenko said: “This is a third such tragic event in recent days, when Ukrainian military An-26 and Su-25 aircraft have been shot down from Russian territory.
“The Ukrainian armed forces did not attempt to shoot down targets in the air.”
Separatist leader Alexander Borodai accused the government of downing the airliner.
“Apparently, it’s a passenger airliner indeed, truly shot down by the Ukrainian air force,” he told Russia’s state-run Rossiya 24 TV broadcaster.
The UK Foreign Office said it was aware of the reports of the crash and was “urgently working to establish what has happened”.
Tony Brenton, a former UK ambassador to Russia, told BBC News it would not be a huge surprise if suspicion initially fell on the rebels. “That would be very damaging both for them and for their Russian supporters,” he said.
“The Russians have undoubtedly been supplying them with weapons, almost certainly with anti-aircraft weapons, so Russia would very likely be implicated and that would raise the volume of international criticism of Russia.”
This is also the second plane crash involving a Malaysian airliner this year, following the disappearance of Flight MH370 to Beijing in March