MOSCOW (Reuters) - The Kremlin confirmed on Thursday that Russian war planes had accidentally killed three Turkish soldiers in an air strike that went wrong in northern Syria, the RIA news agency reported.

Turkey’s military said earlier on Thursday that the Russian strikes had accidentally killed three of its soldiers and wounded 11 others in an operation against Islamic State.

President Vladimir Putin had expressed his condolences to his Turkish counterpart Tayyip Erdogan in a phone call, the Kremlin said.

It said in a statement that the incident had taken place near the Islamic State-held city of al-Bab in northern Syria.

Turkish-backed Syrian opposition fighters resumed a major offensive inside the city on Thursday, a day after they broke through IS defenses in its remaining stronghold in Aleppo province.