Militants shot down a Malaysian airliner over eastern Ukraine Thursday, killing all 295 people aboard, a Ukrainian official said.

The official blamed "terrorists" for using a ground-to-air missile to bring down the Boeing 777 passenger plane, which was en route from Amsterdam to Kuala Lumpur.

Meanwhile, a rebel leader said Ukrainian forces shot the airliner down, but Ukrainian President Petro Poroshenko said the country's armed forces did not fire at any flying object in the region where the plane went down.

In Kuala Lumpur, Malaysian Prime Minister Najib Razak said on his twitter account that he was "shocked by reports that a Malaysian Airline plane crashed," adding that they have launched an immediate investigation.