Two Sukhoi Su-27 pilots have thought to have died after their aircraft crashed while displaying at the Radom Air Show in Poland.
Video footage of the accident, from Polish television, shows the aircraft rolling to the right, inverting and pitching down, before rolling left to a level attitude, but failing to arrest its descent.
Today's display programme had listed a 15min Su-27 display scheduled for 13:15.
Belarus' ministry of defence had previously confirmed that it would provide a Sukhoi Su-27UBM for the show, as well as a Sukhoi Su-24 and Ilyushin Il-76. The crashed Su-27 is said to have been the Belarussian aircraft.
Radom, which lies to the south of Warsaw, hosts a biennial air show. The last event, in 2007, was marred by a fatal mid-air collision involving two Zlin Z-526 aircraft from the Zelazny aerobatic team.