Buk missile launcher, suspected in jetliner attack, requires skill to use

An undated photo shows two "Buk" mobile surface-to-air missile systems during a military parade in Kiev, Ukraine.

Evidence indicates Malaysia Airlines Flight 17 was shot down by a surface-to-air missile in an area of eastern Ukraine controlled by Russian-backed separatists, President Obama confirmed on Friday.

The U.S. government says it's unclear at this point who is responsible for the attack, but security experts agree that whoever launched the strike was using a sophisticated system. Pentagon officials say the missile likely came from an SA-11 or SA-17 launch vehicle -- otherwise known as a "Buk."

Both Russia and Ukraine have Buks, as do most other former Soviet Union states and China. Security experts tell CBS News that no terrorist or extremist groups are known to have these missile launching systems. The whole system consists of multiple vehicles, including one to launch missiles (known as a TELAR), a separate radar vehicle and a command post.

"This isn't an AK-47," John Pike, the director of GlobalSecurity.org, told CBS News. "The thing is a traveling road show."

Pike said the pro-Russian separatists in eastern Ukraine couldn't operate such a system on their own.

"This thing is way too complicated to be operated by anyone other than somebody who does it for a living," he said. "We continue to have a discussion as though... the pro-Russian separatists were somehow independently owned and operated -- they're not."

Anthony Cordesman, a security expert at the Center for Strategic and International Studies, told CBS News that the Buk systems are "technically sophisticated," but he added that the expertise required to operate them might not be out of the separatists' reach. He pointed out that the Russian-backed rebels could have received training, in Russia or in the Ukraine, on earlier models of the Buk.

At least one lawmaker, Sen. Mark Kirk, R-Ill., has said he thinks the separatists would have needed Russian assistance to operate a Buk.

"It does appears the Buk missile system is so complicated that it would need a back-up from a nation state, like Russia," he said on CNN Friday. "That would mean that Russian armed forces are directly involved in this wrongful death of roughly 300 people."

A system like the Buk should have been able to recognize the flight's four-digit transponder code, indicating that it was a civilian plane. , which would have marked it as a civilian plane. It's unclear whether those who fired the missile saw the transponder code.

"The lesson that may come out of this is don't rely on your transponder," Cordesman said.

Cordesman noted the flight could have been mistaken for a Ukrainian aircraft because it was flying the same route a Ukrainian plane would have taken.

While changing flight paths can present a series of challenges for airlines, Cordesman said "it probably was not the brightest thing in the world to be flying over combat zone under the assumption that non-state actors are not going to make mistakes."