A military spokesman for Libya's UN-recognised government says Ilyushin-type planes also flew in ammunitions as part of seven flights to Sirte, Jufra and Benghazi, possibly from different locations.
Russian-made cargo planes have delivered new military shipments to Libyan warlord Khalifa Haftar's militia.
General Abdulhadi Dirah, a spokesperson for the Liban army’s Sirte-Jufra Joint Operations Unit, said on Sunday that Ilyushin-type planes carrying military ammunition conducted five flights to Sirte and Jufra provinces on Saturday.
Two more flights carrying soldiers of the Bashar al Assad regime were made from Syria to Benghazi, the second biggest Libyan city, which is the centre of the Haftar’s militia, Dirah said.
Russia, Egypt and the UAE back eastern-based warlord Haftar, whose militias have been battling the forces of Libya's UN-recognised government, which is supported by Turkey.
Egypt's parliament earlier approved possible military intervention in Libya via the deployment of armed forces abroad to fight "terrorist groups" and "militias".
Battle for Sirte
"There is a military buildup on the ground around Sirte city," TRT World's Sara Firth said from Tripoli.
The Libyan government forces have moved closer to the central city of Sirte, the gateway to oil-exporting ports that they hope to recapture from Haftar's militias.
Egypt has declared the Sirte front line "a red line" for Egypt.
Turkish and Russian meetings carry weight because both sides are two major foreign backers in Libya conflict, who are now "trying to pull things back from the brink of a military confrontation," Firth said.
On July 24, the US military shared evidence of Russia sending more military equipment to its mercenaries in Libya, including Sirte, in breach of an arms embargo.
The US Africa Command said there was mounting evidence from satellite pictures of Moscow's military cargo planes, including IL-6s, bringing supplies to fighters from the Russian Wagner Group.
Haftar's militia has also sent fighters and weapons to bolster its defence of Sirte, already badly battered from earlier phases of warfare and chaos since the 2011 revolution.
Libya has been torn by violence since the 2011 ouster of long-time dictator Muammar Gaddafi in a NATO-backed uprising, and the conflict has since drawn in multiple foreign powers.