Russia police say thieves have stolen equipment and components from the Ilyushin-80 "Doomsday" plane - an airborne command center built to keep officials alive and in control of the military in the event of a nuclear attack, Fox News reported Thursday.

The burglary, which raises doubts about the security of classified military hardware, took place as maintenance work was being conducted on the Ilyushin at the Taganrog aviation, scientific and technical complex.

The thieves broke into the top-secret plane's cargo bay and stole nearly 40 pieces of radio equipment. Russia military experts said the hardware was stolen because some of it contained precious metals like platinum and gold.

Russia broadcaster Ren-TV reported police had found shoe and fingerprints on the plane but haven't identified any suspects.

Security has been tightened, the Kremlin - which is investigating the theft - said. Few details about Doomsday are known.

Authorities gave no details about a motive for the theft except for the estimated value of the stolen equipment - more than a million rubles ($13,600).

Russia has four Ilyushin-80s, customized Il-86s that are equipped to protect passengers during a nuclear conflict.

The U.S. maintains four Boeing E-4 advanced airborne command posts, modified Boeing 747-200s designed to carry the president and other military officials in case of nuclear war.

President Vladimir Putin's press secretary Dmitry Peskov said the theft was an "emergency situation."  "Of course, there'll be an investigation and measures will be taken so that this doesn't happen again," CNN quoted the official as saying.