The junta-led country's relations with Moscow have been in the spotlight since it booted out French troops in early 2023, fuelling speculation it would deepen security ties with Russia like neighbouring Mali, where Russian Wagner mercenaries operate.
The foreign sources in Ouagadougou did not have further details on the apparent deployment.
The African Corps channel on the Telegram messaging app, which claims affiliation with Russia's Defence Ministry, said a group of 100 servicemen had flown to Burkina Faso to "ensure the safety of the country's leader Ibrahim Traore and the Burkinabe people."
A further 200 would be deployed in the near future, it said on Wednesday.
The Russian defence ministry did not reply to a request for comment.
Photos posted to Telegram on Wednesday by African Initiative, a pro-Kremlin Russian news agency that covers African affairs, showed men in army fatigues unloading equipment from a plane with a Russian flag and a blurred number on its tail.
The aircraft pictured on the sunbaked tarmac was an Il-76, long the workhorse of the Russian military.
African Initiative said the photos showed the arrival in Ouagadougou of the 100 Russian servicemen, who it said would also train their Burkinabe counterparts and help patrol dangerous areas.
Reuters could not immediately verify the photos or the information.
The deployment will add to Western concerns about Russia's widening influence in Africa's Sahel region, where a series of coups has swept Moscow-friendly juntas to power in Mali, Niger and Burkina Faso, reshaping a long-running regional conflict with insurgents linked to Islamic State and Al Qaeda.
Further cooperation could be on the horizon. The military leaders of Niger and neighbouring Chad paid separate official visits to Moscow in January.
(Reporting by David Lewis in Nairobi, Gleb Stolyarov and Felix Light in Tbilisi; Additional reporting and writing by Alessandra Prentice; Editing by Ros Russell)
