Malaysia Airlines Flight MH17 was brought down by a Russian-made Buk missile over rebel-held territory in eastern Ukraine on July 17, 2014, the Dutch Safety Board announced Tuesday. At a separate briefing, authorities also revealed details to relatives of the victims about the plane's downing that killed all 298 people on board.

Tjibbe Joustra, Dutch Safety Board chairman, said that the missile first hit the left side of the cockpit -- adding that the plane broke up on impact, scattering debris over a 19-square-mile area -- and blamed Ukrainian authorities for failing to close the airspace. Joustra added that three crew members were killed in the cockpit when the missile hit. Investigators ruled out other potential factors such as a bomb, air-to-air strikes or a meteor strike. At the same time, they also noted that airlines flying over the war-torn area should have recognized the dangers.

“None of the parties involved recognized the risk from the armed conflict on the ground,” Joustra said, adding: "Nobody gave a thought to a possible threat to civil aviation."

Planes from 61 airlines were flying over eastern Ukraine at the time of the disaster, the Dutch team reportedly said at a press conference at the Gilze-Rijen air force base in the Netherlands. 

Meanwhile, relatives of the victims also revealed details of the report ahead of its official release later Tuesday. The relatives were told that all the passengers died or lost consciousness as soon as the missile hit the plane. Relatives also reportedly said that Buk missile shrapnel was found inside the bodies of some of the crew members. The first copies of the Dutch report has been handed over to the victims’ next-of kin at The Hague.

“We can’t be 100% sure [that nobody suffered on the flight] but we’ve got to sort of think that was the case,” Barry Sweeney, a father of one of the victims, told BBC.

Earlier on Tuesday, Russian arms manufacturer Almaz-Antey, which makes the Buk missiles, said that its independent investigation contradicts the findings of the Dutch probe into the crash.

"Today we can say for sure that the Malaysian Boeing was shot down by a Buk missile 9M38 from direction Zaroshenskoye," Almaz-Antey CEO Yan Novikov reportedly said Tuesday, during a briefing in Moscow, without specifying what was in the report. "During the experiment it became perfectly clear that, if MH17 was brought down by a BUK-M1 missile, that was the 9M38 missile, which has no strike elements shaped as I-beam."

MH17 russia Russia's missile maker Almaz-Antey's chief executive, Yan Novikov, holds a press conference to present the results of the company's investigation into the downing of Malaysia Airlines flight MH17 in Moscow, Oct. 13, 2015. Photo: Getty Images/Vasily Maximov/AFP

According to the Guardian, a Dutch official heading the investigation dismissed the attempts to divert attention from the official investigation. “It’s always special when people already know that they don’t agree with a report that’s not even published yet,” DSB's Joustra said.

Ukraine and Western governments have blamed Russian-backed separatists for downing the plane, most likely by using an SA-11 surface-to-air missile system known as a Buk. Russia has steadfastly denied allegations of shooting down the aircraft. 

Joustra also confirmed that the Russian government challenged the report's finding and said that such a conclusion could not be made with certainty.

“The DSB has extensively studied the comments provided by the Russian Federation,” Joustra reportedly said, rejecting Russia's claims, adding that its response to Russia’s objections are spelled out in an appendix to the report.

A preliminary report of an investigation into the crash by Dutch investigators, released in September 2014, stated that the jetliner broke apart in mid-air after being hit by “a large number of high-energy objects that penetrated the aircraft from outside.”