Ukrainian President Petro Poroshenko called the downing an act of terrorism and called for an international investigation into the crash. He insisted that his forces did not shoot down the plane.

President Barack Obama called the crash a "terrible tragedy" and talked about it on the phone with Russian President Vladimir Putin.

The village of Hrabove is currently under the control of pro-Russia separatists and the area has seen severe fighting between the two sides in recent days.

Aviation authorities in several countries, including the FAA in the United States, had issued warnings not to fly over parts of Ukraine prior to Thursday's crash. Within hours, several airlines, including Lufthansa, Delta and KLM, released statements Thursday saying they were avoiding parts of Ukrainian airspace.

Malaysia Airlines said Ukrainian aviation authorities told the company they had lost contact with Flight MH17 at 1415 GMT (10 a.m. EDT) about 30 kilometers (20 miles) from Tamak waypoint, which is 50 kilometers (30 miles) from the Russia-Ukraine border.

It said the plane was carrying 280 passengers and 15 crew members. It had left Amsterdam at 12:15 p.m. and was due to arrive at Kuala Lumpur International Airport at 6:10 a.m. Friday.

Anton Gerashenko, an adviser to Ukraine's interior minister, said on his Facebook page the plane was flying at an altitude of 10,000 meters (33,000 feet) when it was hit by a missile from a Buk launcher, which can fire up to an altitude of 22,000 meters (72,000 feet).

Igor Sutyagin, a research fellow in Russian studies at the Royal United Services Institute, said both Ukrainian and Russian forces have SA-17 missile systems — also known as Buk ground-to-air launcher systems.

He said Russia had supplied separatist rebels with military hardware, but he had seen no evidence "of the transfer of that type of system from Russia." The weapons that the rebels are known to have do not have the capacity to reach beyond 4,500 meters. (14,750 feet)

A launcher similar to the Buk missile system was seen by Associated Press journalists earlier Thursday near the eastern Ukrainian town of Snizhne, which is held by the rebels.

The Malaysia Airlines plane was delivered to the company on July 30, 1997, according to Flightglobal's Ascend Online Fleets. It has more than 43,000 hours of flight time and 6,950 takeoffs and landings.

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."

The Kremlin said Putin "informed the U.S. president of the report from air traffic controllers that the Malaysian plane had crashed on Ukrainian territory" without giving further details about their call. The White House confirmed the call.

Separatist leader Andrei Purgin told The Associated Press that he was certain that Ukrainian troops had shot the plane down, but gave no explanation or proof for his statement.

Purgin said he did not know whether rebel forces owned Buk missile launchers, but said even if they did, they had no fighters capable of operating it.

Around the time the plane crashed, Russian media quoted witnesses as saying they saw a plane being hit by what they thought was a rocket.

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.

Dutch Prime Minister Mark Rutte, who had been attending a European Union summit in Brussels, headed back to the Netherlands to deal with fallout from the crash.

There have been several disputes over planes being shot down over eastern Ukraine in recent days.

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. 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 after his jet was shot down.

Russia's U.N. Ambassador Vitaly Churkin told reporters at U.N. headquarters in New York on Thursday that Russia did not shoot down the Ukrainian fighter jet on Wednesday. "We didn't do it," Churkin said.

Pro-Russia rebels, meanwhile, claimed responsibility for strikes Wednesday on two Ukrainian Sukhoi-25 jets.

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.

Earlier this week, Ukraine said a military transport plane was shot down Monday over eastern Ukraine by a missile fired from Russian territory.

Many airlines had continued to use the route despite warnings not to because of the fighting, said Norman Shanks, former head of group security at airports group BAA and professor of aviation security at Coventry University in England.

"It is a busy aviation route and there have been suggestions that a notice was given to aviators telling airlines to avoid that particular area," Shanks said.

"But Malaysia Airlines, like a number of other carriers, have been continuing to use it because it is a shorter route, which means less fuel and therefore less money."

Flights that were airborne when the Malaysia Airlines jet crashed have been re-routed, transportation officials said.

Other passenger planes have been shot down before including:

— April 20, 1978: Korean Airlines Flight 902, which diverted from its planned course on a flight from Paris to Seoul and strayed over the Soviet Union. After being fired upon by an interceptor aircraft, the crew made a forced landing at night on the surface of a frozen lake. Two of the 97 passengers were killed by the hostile fire.

— Sept. 1, 1983: Korean Air Lines Flight 007 shot down by at least one Soviet air-to-air missile after the 747 had strayed into Soviet airspace. All 240 passengers and 29 crew were killed.

— July 3, 1988: Iran Air Flight 655 Aircraft was shot down by a surface to air missile from the American naval vessel U.S.S. Vincennes. All 16 crew and 274 passengers were killed.