Ukraine says it can prove Russia supplied arms system that downed MH17

We have proof that the terrorist attack was planned and carried out with the involvement of representatives of the Russian Federation… We know that Russia is trying to hide its terrorist activity and their direct involvement.

— Vitaly Nayda, the head of counterintelligence for the Ukrainian State Security Service, expressing his government’s conclusion that Russia was directly involved in the attack that brought down Malaysian Airlines Flight 17.