Russia blamed the misdirected strikes on poor coordination between Moscow and Ankara
Russian air strikes accidentally killed three Turkish soldiers and wounded 11 others during an operation against Islamic State in northern Syria on Thursday, the Turkish military said.
"During an operation by a Russia Federation warplane against Islamic State targets in the region of the Euphrates Shield operation in Syria, a bomb accidentally hit a building used by Turkish Army units," the military said in statement.
The Kremlin said Russian President Vladimir Putin had called Turkish counterpart Tayyip Erdogan and expressed his condolences, blaming the misdirected strikes on poor coordination between Moscow and Ankara.
The incident highlighted the risk of unintended clashes between the numerous outside powers involved in Syria's complex six-year-old war. Besides Russia and Turkey, they include Lebanon's Hezbollah and other Iranian-backed militias, and members of a U.S.-led coalition fighting Islamic State.
Russia supports Syrian President Bashar al-Assad, while Turkey supports the rebels opposing him.
In 2015, Turkey shot down a Russian air force jet that it said had crossed into Turkish airspace, though Moscow denied that happened.
The two countries have since repaired relations, and Thursday's Kremlin statement said the two leaders had agreed to step up military coordination against Islamic State.