Investigators in Russia are working to determine what caused two passenger jets to crash almost simultaneously late Tuesday, killing all 89 people aboard.
Officials have not ruled out terrorism, but say they are also looking into technical failure or other problems.
President Vladimir Putin ordered the country's security agency to investigate.
Both planes took off from Moscow's Domodedovo airport within an hour of each other. One of the aircraft activated a distress signal before going down.
One crash site is in the Tula region, about 180 kilometers south of Moscow. Residents reported hearing an explosion before the crash. The bodies of all 43 people aboard that plane have been recovered.
The other aircraft, with 46 passengers and crew, was found near the southern city of Rostov-on-Don.
The flight recorders of both planes have been recovered.
Information for this report is provided by AP, AFP and Reuters.