Reports of funerals of Russian paratroopers need to be checked, President Vladimir Putin's spokesman said late Wednesday as media speculation mounted over whether the men were killed in action in Ukraine.
"It goes without saying, no doubt this information is being checked by the necessary bodies," Peskov was quoted as saying by the ITAR-TASS news agency.
"This needs to be checked in detail before drawing any conclusions," Peskov told journalists.
Asked whether checks were ongoing, he said: "I don't know for sure, so I won't say."
Russian independent media has reported widely on the funerals of two paratroopers in northwestern Russia, held in secret, citing mourners as saying they were killed in Ukraine, where Russia says it does not have troops deployed.
Russia's acknowledgement this week that its troops were in Ukraine -- albeit accidentally -- has prompted a storm of questioning about what Russia is doing in war-torn eastern Ukraine.
Ukraine on Monday said its military had captured 10 Russian paratroopers more than 20 kilometres (12 miles) from the border and showed video footage of the men on television.
A source in the Russian defence ministry later told state news agencies the paratroopers had apparently strayed into Ukrainian territory by accident.
The leader of the Donetsk rebels, Alexander Zakharchenko, said Wednesday that many Russian troops were fighting alongside his insurgents, but said they had all chosen to spend their holidays in the Donetsk region.
TV Rain station reported Wednesday that the head of a regional branch of the Committee of Soldiers' Mothers, a rights group that campaigns against abuses in the armed forces, had drawn up a list of 400 soldiers believed to have been injured or killed in Ukraine.
The rights council that advises Putin on Tuesday asked for a criminal investigation into another incident in which nine professional soldiers died while apparently on a training exercise in a southern Russian region bordering Ukraine.