Syria's state media say the U.S.-led coalition has bombed government-backed troops in eastern Syria, citing reports of dozens killed and wounded.
The official state news agency SANA reported on Thursday that the overnight attack hit tribal fighters in Khusham, a town in the oil-rich Deir el-Zour province.
SANA says the local fighters were battling IS militants and the U.S.-backed Kurdish-led Syrian Democratic Forces in the area. The U.S. military said late Wednesday it launched airstrikes on Syrian government-backed troops after as many as 500 attackers began what appeared to be a coordinated assault on the SDF accompanied by U.S. advisers in Deir el-Zour province.
Turkish officials say the leaders of Turkey, Russia and Iran will meet in Istanbul to discuss peace efforts for Syria.
The officials said that Turkish President Recep Tayyip Erdogan and his Russian counterpart Vladimir Putin agreed to the summit during a telephone call on Thursday.
It was not immediately clear when the Istanbul meeting would take place.
The Turkish officials said two leaders also agreed that efforts to create "observation posts" in Syria's Idlib province as part of a "de-escalation" agreement between Turkey, Russia and Iran should gain momentum.
They discussed the humanitarian situation in Eastern Ghouta, just outside Damascus, where dozens have been killed in aerial strikes in the past few days.
The officials provided the information on condition of anonymity in line with government rules.