GILZE-RIJEN AIR BASE, Noord-Brabant, The Netherlands -- All civilian air traffic should have been banned in eastern Ukraine on July 17 last year, the Dutch Safety Board concluded in its final investigation report on the MH17 disaster published on Tuesday.

"Everyone thought it was safe, nobody thought that civil aviation was at risk," Safety Board director Tjibbe Joustra said during a presentation at Gilze-Rijen Air Base. "Between July 14 and 17 a total of 61 operators from 32 countries flew above eastern Ukraine until the closure of the airspace after the crash. On July 17, 160 civilian airplanes flew over the area and at the moment of the crash three other commercial airlines were nearby."

"In the months before the crash several military aircrafts were shot down," Joustra added. "The Ukrainian authorities were aware of this. Despite of all this Ukraine did not close the airspace. As a precaution there was sufficient reason to close the airspace above the eastern part of the country."

Air traffic restrictions had been in force over eastern Ukraine since July 1, 2014 because of the hostilities in the conflict between pro-independence militants and Ukrainian government troops. Since July 14, 2014, the minimum altitude was increased to 9.7 km and the Malaysia Airlines MH17 flew above that minimum height on July 17.

On behalf of the Safety Board, Joustra issued three recommendations to avoid a similar disaster in the future. "States involved in an armed conflict should put more effort in guaranteeing the safety of the airspace for civil aviation, other states involved should be more aware of the risks, should improve the risk analyses and operators should be more transparent on flight routes."

The Boeing 777 Malaysian Airlines flight MH17 crashed in eastern Ukraine on July 17 last year on its way from Amsterdam to Kuala Lumpur. All 298 people, 283 passengers and 15 crew members, died.