Russia says its embassy in the Syrian capital has been hit by mortar fire.

The Foreign Ministry said in a statement Wednesday that a mortar round landed in the embassy courtyard without exploding, and another fell in the vicinity. The ministry says sappers have been called in to remove the device.

Russian officials blamed the attack on “extremists” opposed to a peaceful settlement of Syria’s conflict.

Russia is a key ally of Syrian President Bashar Assad, who has been battling a revolt against his family’s four-decade rule since 2011.