A Russian warplane veered off a runway at the country's air base in Syria and suffered damage, killing its crew, the Defense Ministry in Moscow said.
The Sukhoi Su-24 jet was taking off from the Hmeymim air base on a combat mission when it went off the runway and "was destroyed," state-run news agency TASS and other Russian media quoted the ministry as saying.
"The airplane's crew was unable to eject and died," the ministry said, adding that a technical problem was one possible cause of the crash.
The Su-24 normally has a crew of two.
Moscow has given President Bashar al-Assad's government crucial military and diplomatic support throughout the more than six-year war in Syria, which began with a crackdown on pro-democracy protesters.
Russia began a campaign of air strikes in support of Assad's government in September 2015 and has also stepped up its military presence on the ground in the Middle Eastern country.
Based on reporting by TASS, RIA Novosti, and Interfax