MOSCOW, February 11. /TASS/. Flights of the Sukhoi Su-24 jets have been suspended until the causes of the Wednesday morning crash of this type of aircraft that took place outside Volgograd are investigated, the press service of the Russian Defense Ministry reported.

The Su-24 jet crashed seven kilometers from the runway. The fate of its crewmembers is unknown so far. A law enforcement source told TASS that the pilots have presumably ejected.

"On the order of the Chief of the General Staff of the Russian Armed Forces flights of the Su-24 planes are suspended until the causes of the accident are investigated," the press service said.

The Defense Ministry has earlier established a special commission to investigate the crash causes and a search and rescue team has been dispatched to the accident area. The Su-24 flight was performed without combat ammunition load by experienced pilots who have more than 1,000 logged flight hours each, the ministry said.

The Sukhoi Su-24 twin-engine frontline bomber was developed in the Soviet Union. The modified version, Su-24M, entered service in 1983 and is still in use by some former Soviet states. In 2010, the Russian Air Force decided to replace its Su-24s with modern Su-34s.