UPDATE 4:15 p.m.: U.S. intelligence officials have confirmed that an anti-air missile downed the plane, though they have yet to determine who shot it, according to The Wall Street Journal.
A Malaysia Airlines plane has reportedly been shot down over Ukraine, a Ukrainian interior ministry official told the Associated Press. Malaysia Airlines has confirmed that it lost contact with the plane, MH17, over Ukraine, though it did not provide any other information.
The Ukrainian official, Anton Gerashchenko, claimed in a Facebook message that pro-Russian separatists downed the airliner with a Buk missile. However, the rebels denied any involvement, saying they did not have the necessary firepower to bring down a jet.
A Voice of Russia report last month claimed the Donetsk People's Republic — a rebel group — had taken control of an eastern Ukrainian military base equipped with anti-aircraft missiles. Rebel forces also reportedly downed a military jet earlier this week, one month after they claimed credit for taking out a military transport aircraft as it prepared to land in Luhansk, killing 49.
MH17 was flying from Amsterdam to Kuala Lumpur, and was reportedly carrying 295 people.
The White House said President Obama had been briefed about the plane crash.