Ukrainian President Petro Poroshenko called the downing of a Malaysian Airlines passenger plane in Ukrainian airspace an "act of terrorism”, not ruling out that the Malaysia Airlines flight may have been shot down.

“We do not exclude that the plane was shot down and confirm that the Ukraine Armed Forces did not fire at any targets in the sky,”- Poroshenko said in a statement posted on the president’s website. 

Poroshenko said he had spoken with the Dutch Prime Minister Mark Rutte and that Ukraine had offered its condolences on behalf of the Ukrainian people.

He also called for an international investigation into the crash.

A Ukrainian Interior Ministry adviser, Anton Herashchenko, earlier claimed the plane had been shot down by a BUK ground-to-air missile and killed all of the nearly 300 people on board.

Both the government in Kiev and the pro-Russia separatists who have been fighting in the Donetsk region denied any responsibility for downing the plane, which was carrying 295 people.