All flights by Su-27 fighters have been suspended by the commander of Russia’s Aero-Space Force until it is clear what caused the crash of a plane of this type near Moscow on Thursday morning, the Defense Ministry said.

"According to preliminary findings, technical problems were to blame," the ministry’s statement says.

Earlier, a source in the panel of inquiry told TASS all Su-27 had been grounded.

According to a source in the panel of inquiry has told TASS, the black box of the crashed warplane is in good condition.

"The ‘box’ has been found, it is one, it is in a good condition," the source said.

The Su-27 warplane of the Russian Knights aerobatic team crashed in the Pushkinsky district in the Moscow Region earlier on Thursday after the aerobatic team took part in a ceremony of opening a monument to aviators in Ashukino. 

Earlier, the Defense Ministry said the Su-27 may have crashed due to technical problems. The pilot was killed in the crash. According to the ministry, the pilot did all he could to steer the plane away from a nearby community and had no time to eject himself.