Russian news agencies denied reports that a Russian general had been killed in Syria and said he had appeared in person on Wednesday at the Defense Ministry in Moscow.
The ministry said reports that a Russian general advising Syria's military had been killed amounted to a "bald-faced lie".
Itar-Tass news agency said a reserve officer called Vladimir Kuzheyev had later met Russian journalists at the ministry and, although he did not say whether he had been in Syria, he declared: "I want to confirm that I am alive and well."
Rebels fighting the regime of Syrian President Bashar Assad announced earlier Wednesday that they had killed a Russian general working as a consultant to the Syrian defense minister on the outskirts of the capital Damascus.
The Free Syrian Army said in a statement that it killed Vladmir Petrovic Kojaiv, adding that this was evidence Russia was embroiled in the ongoing Syrian conflict.
"With the help of God, the Russian adviser for the minister of defense for military scientific affairs, General Vladimir Petrovich Kochyev, has been eliminated with his personal translator, Ahmad a-Ayyouq," Lieutenant Majid Sayyed Ahmad of the Syrian rebels' Hawks battalion said in a video.
"A number of Syrian army documents have been also seized, together with reports about the opposition and the Free Syrian Army, adding to the achievements on the road to the liberation of Syria from the Assad gang," said Ahmad, who gave his title as "commander of operations and special assignments."
Russia, which has an estimated several hundred military personnel in Syria, is one of the few countries still backing Assad diplomatically since a popular uprising against his rule erupted 17 months ago.
Also Wednesday, Iran's Foreign Minister Ali Akbar Salehi said that some of the Iranians kidnapped by Syrian rebels are retired members of Iran's Islamic Revolutionary Guard Corps and military.
"Some of these (Iranians) were retired IRGC and military members... and others were from other different departments," Salehi said, according to the Iranian Students' News Agency, though he denied they now have any military connection and insisted they were in Damascus for a religious pilgrimage.
Salehi said retired government employees from a number of agencies had signed up to make pilgrimages to Damascus after recent fighting in the Syrian capital had subsided.
"After some time in which pilgrims from Iran were not being dispatched to Syria...we took steps to send retired forces from various organizations," Iran's state news agency IRNA quoted Salehi as saying.
"Some retired individuals from the Guards and army were dispatched to Syria to make a pilgrimage."