BEIRUT (AP) — The Latest on the conflict in Syria (all times local):
Turkey has complained about a lack of aerial support from the U.S.-led coalition for its operations against the Islamic State group in northern Syria.
Presidential spokesman Ibrahim Kalin told reporters Monday that the coalition "needs to carry out its responsibilities especially on the issue of providing aerial backing."
His comments come days after Turkish troops, trying to recapture the IS-held town of al-Bab, suffered heavy casualties. A total of 16 Turkish soldiers were killed in fighting in al-Bab last week and a 17th soldier died Monday from his previous injuries.
Turkey sent ground troops into northern Syria in August to assist Syrian opposition forces in clearing a border area of IS militants and to prevent Syrian Kurds from making greater territorial advances.
At least 38 Turkish soldiers have been killed in northern Syria since then.
The Russian Defense Ministry says its troops have found mass graves in Aleppo with bodies showing signs of torture and mutilation.
Ministry spokesman Maj. Gen. Igor Konashenkov said in an emailed statement on Monday that the Russians found "found mass graves of several dozens of Syrians who suffered atrocious torture and massacre."
Konashenkov said some of the bodies have been mutilated and some had gunshot wounds.
The Russian Air Force has helped Syrian President Bashar Assad and its allies to capture Syria's largest city after weeks of a siege. Russian has since dispatched military police to the city.
Konashenkov also criticized the opposition rebels, who controlled eastern Aleppo before they were pushed out earlier this month, for laying multiple booby traps and mines across town, endangering the civilian population.
Syrian President Bashar Assad has visited a Christian orphanage near the capital Damascus on Christmas Day.
Photographs posted on the Syrian presidency's Facebook page showed the president along with his wife, Asma, standing with nuns and orphans in the Damascus suburb of Sednaya.
In the northern city of Aleppo, Christians celebrated Christmas for the first time in four years with the country's largest city now under full control of government forces.
The rebel withdrawal from east Aleppo last week marked Assad's biggest victory since Syria's crisis began in 2011.
Christians, one of the largest religious minorities at about 10 percent of Syria's pre-war 23 million-strong population, have tried to stay on the sidelines of the conflict. However, the opposition's increasingly outspoken Islamism has kept many leaning toward Assad's government.