MOSCOW (AP) — The Russian defense ministry says two Russian troops have been killed in shelling in Syria's east.

The ministry's statement quoted by Russian news agencies late on Monday said the two men died when a convoy escorting Russian cease-fire monitoring staff came under mortar fire outside the eastern city of Deir el-Zour.

The ministry said one man died on the spot and the other died later of wounds in a hospital.

Russia has been providing air cover for Syrian President Bashar Assad's offensive against Islamic State group militants since 2015. The Russian defense ministry said Monday that Russian jets had made 80 flights to back Assad's offensive on Deir el-Zour, a key city that has been under IS siege for three years.