Russian Defense Ministry: Russian buk missiles have never crossed the Ukrainian border

Defense Ministry spokesman Igor Konashenkov said that Russian self-propelled, medium-range surface-to-air missile systems, including Buk launchers, have never crossed the Russian-Ukrainian border.

He also said that the validity of the findings of an international investigation concluding that a Russian Buk surface-to-air launcher brought into Ukraine was used to shoot down flight MH17 in July 2014 could not possibly be "doubted" as it was based on "two main sources: the Internet and Ukraine's security services."

"We are most interested in conducting an objective investigation and in establishing the true culprits of the disaster on July 17, 2014. And we will continue to provide all necessary assistance," said Konashenkov.

On September 28, an international investigation committee released a preliminary report into the shooting down of Malaysian Airlines civil airliner MH17 over Donetsk. The investigation concluded that the aircraft was shot down by a missile fired from a Buk missile system in separatist-controlled territory six kilometers south of the city of Snezhnoe. The system, according to investigators, was brought to the area from Russian territory and later was returned to the Russian Federation.

MH17 had 298 people on board, all of whom died.