Anton Gerashenko, an adviser to Ukraine’s interior minister, said on his Facebook page the plane was flying at an altitude of 33,000 feet (10,000 meters). He also said it was hit by a missile fired from a Buk launcher, which can fire missiles up to an altitude of 72,000 feet (22,000 meters).
The fate of the passengers wasn’t immediately known.
Ukrainian President Petro Poroshenko said his country’s armed forces didn’t shoot at any airborne targets.
“We do not exclude that this plane was shot down, and we stress that the Armed Forces of Ukraine did not take action against any airborne targets,” he said. “We are sure that those who are guilty in this tragedy will be held responsible.”
Malaysia Airlines said on its Twitter feed that it “has lost contact of MH17 from Amsterdam. The last known position was over Ukrainian airspace.” The plane’s destination was Kuala Lumpur.
It was the second time that a Malaysia Airlines plane was lost in less than six months. Malaysia Airlines Flight 370 disappeared in March while en route from Kuala Lumpur to Beijing. It has not been found, but the search has been concentrated in the Indian Ocean far west of Australia.
Malaysian Defense Minister Hishamuddin Hussein said on Twitter there’s no confirmation that Thursday’s plane was shot down. He said he has instructed the country’s military to check and get confirmation.
The Donetsk region government said Thursday’s plane crashed near a village called Grabovo, which it said is currently under the control of armed pro-Russian separatists. The region where the flight was lost has seen severe fighting between Ukrainian forces and pro-Russia separatist rebels in recent days.
A launcher similar to the Buk missile system was seen by Associated Press journalists near the eastern Ukrainian town of Snizhne, which is held by pro-Russia rebels, earlier Thursday.
On Wednesday evening, a Ukrainian fighter jet was shot down by an air-to-air missile from a Russian plane, Ukrainian authorities said Thursday, adding to what Kiev says is mounting evidence that Moscow is directly supporting the separatist insurgents in eastern Ukraine. Security Council spokesman Andrei Lysenko said the pilot of the Sukhoi-25 jet hit by the air-to-air missile was forced to bail out.
Pro-Russia rebels, meanwhile, claimed responsibility for strikes on two Ukrainian Sukhoi-25 jets on Wednesday. The Ukrainian Defense Ministry said the second jet was hit by a portable surface-to-air missile, but added the pilot was unscathed and managed to land his plane safely.
Moscow denies Western charges that is supporting the separatists or sowing unrest in its neighbor. The Russian Defense Ministry couldn’t be reached for comment on Thursday about the Ukrainian jet and Russia’s foreign ministry didn’t respond to multiple requests for comment.
Earlier this week, Ukraine said a military transport plane was shot down on Monday by a missile fired from Russian territory.
The Malaysia Airlines plane is a Boeing 777-200ER, which was delivered to Malaysia Airlines on July 30, 1997, according to Flightglobal’s Ascend Online Fleets, which sells and tracks information about aircraft. It has more than 43,000 hours of flight time and 6,950 takeoffs and landings.