International investigators say Malaysia Airlines flight MH17 was shot down last year by a Russian-made missile.

The airplane crashed in eastern Ukraine on July 17, 2014. All 298 passengers and crew were killed.

Dutch officials announced the investigation findings Tuesday in the Dutch capital, The Hague.

The Dutch Safety Board led the investigation. Its chairman, Tjibbe Joustra, spoke to family members and media. He said the plane was hit by pieces from a missile explosion. He said the missile was fired from the ground. He also said the plane broke apart while still in the air.

He said Ukraine was responsible for not closing its airspace. Russian-backed rebels and Ukrainian forces were fighting below the flight path.

Nobody considered the possibility that civil aircraft at cruising altitude was at risk, he said.

Mr. Joustra said nations in armed conflict should put more effort into the safety of their airspace.