The U.S.-led coalition fighting the Islamic State group says it hit pro-Syrian government forces near the border with Jordan that "posed a threat" to U.S. forces and rebel groups in the area.
The coalition statement late on Thursday says the coalition hit the pro-Syrian government forces after warning shots, a show of force and apparent Russian attempts failed to dissuade those troops from moving into the "de-conflicted area."
The de-conflicted zone, agreed between the United States and Russia, is located around Tanf, where the borders of Jordan, Syria and Iraq meet.
The statement says coalition forces have been operating in the area "for many months training and advising vetted partner forces" in the battle against IS.
Syrian activists say the strike destroyed vehicles and left casualties. There was no immediate word from the government, Iranian troops or Hezbollah militants on any casualties.
U.S. officials say an American airstrike has hit pro-Syrian government forces in southern Syria as they were setting up fighting positions in a protected area.
The officials say the strike near Tanf hit a tank and a bulldozer and forces there, but it was not clear if they were Syrian army troops or other pro-government allies.
One official says the pro-regime forces had entered a so-called "de-confliction" zone without authorization and were perceived as a threat to U.S.-allied troops there. The officials say the strike was a defensive move to protect the U.S. allies. It wasn't clear if U.S. forces were there.
The officials weren't authorized to speak publicly on the matter and demanded anonymity.
Syrian opposition activists say a suspected coalition airstrike has hit a convoy of pro-government forces in the desert near the border with Jordan.
There was no immediate response from the U.S.-led coalition following the reports. A U.S. official confirmed that an airstrike in southern Syria occurred on Thursday, though it was unclear if Syrian government troops were there. The official was not authorized to talk publicly on the matter and spoke on condition of anonymity.
Several Syrian opposition media groups with activists in the area say the airstrike hit a convoy of government troops and allied militiamen on the road to the Tanf area, where Syria's borders with Jordan and Iraq meet.
One opposition media group, the Palmyra News Network, says the attack at the Zarka juncture, about 27 kilometers or 17 miles from the border, destroyed a number of vehicles and caused casualties.
The area has been a source of tensions as both government forces and U.S.-backed rebels advance there. Both the government forces and the rebels are trying to rout Islamic State militants from the area.
The Revolutionary commandoes or Maghaweer al-Thawra, a U.S.-backed group, shared a report about the airstrike on their Twitter account.
Syria state news agency says President Bashar Assad has met with Iraq's national security adviser to discuss steps to improve coordination between their countries' militaries in the anti-terrorism campaign along their shared border.
SANA news agency says Assad and Faleh al-Fayad on Thursday discussed "practical" measures to strengthen cooperation in fighting terrorism — a reference to the war against Islamic State militants.
Syrian officials have said that taking Deir el-Zour, an oil-rich province straddling the border with Iraq, from IS militants is a priority. There is a new government offensive underway in the country's east, in an area where U.S-backed rebels are also fighting against IS.
The head of the Syrian government delegation at the U.N.-mediated talks underway in Geneva says his team led the drive to start "informal meetings" on a constitutional process.
Bashar al-Ja'afari, who is also Syria's U.N. ambassador, says the subject was brought up on the government's "own initiative," but insisted that Damascus "will not accept any interference" on the constitution.
Thursday's announcement of the talks-within-talks among constitutional experts appear to be the only development so far in the sixth round of largely unproductive discussions that have been
by U.N. envoy Staffan de Mistura since early 2016.
Al-Ja'afari said he hoped the agreement would "help in pushing this round forward" and insisted it had "nothing to do" with possible political transition sought by the opposition.
The envoy's office said his team also met separately on Thursday with opposition experts on constitutional and legal issues.
Syrian state media and monitoring group say that at least 15 civilians have been killed in an Islamic State offensive on a government-held area in Syria.
The reports gave different death tolls for the IS attack on the village of Aqarab al-Safiyeh in central Syria.
State news agency SANA says 20 civilians were killed after IS militants stormed parts of the village and that 45 were wounded. The agency says women and children were among the dead, and that some were beheaded.
The Britain-based Syrian Observatory for Human Rights says 52 people were killed in the fighting, with the dead including 15 civilians, 27 Syrian soldiers and 10 unidentified people.
According to the Observatory, IS attacked several government-held villages in the area on Thursday, capturing parts of them. Most of the residents belong to the Ismaili branch of Shiite Islam.
The United Nations special envoy for Syria says discussions have begun on a constitutional process as part of his mediation efforts to end the six-year-old civil war.
The office of Staffan de Mistura said Thursday there would be an expert-level meeting with representatives of the Syrian government delegation "on issues and ideas on constitutional process."
Meanwhile, the Syrian opposition said in a statement it sought clarification on 13 points including the mandate of the body and its frame of reference.
The envoy's proposal said the aim was to avoid a legal "vacuum" during an eventual political transition period.
Opposition spokesman Salem Meslet says talks are focusing on "the constitutional ground for a political transition process based on the formation of a body with full executive powers."
The Islamic State group has launched an offensive against government forces in central Syria near the highway that links the capital Damascus to the northern city of Aleppo.
Thursday's attack comes as government forces are on the offensive against the extremists in other parts of Syria.
Syria's state news agency SANA said troops and pro-government gunmen repelled the IS attack on villages in Hama province.
The Britain-based Syrian Observatory for Human Rights said IS captured several army positions in the area and killed nine troops. It said troops launched a counteroffensive under the cover of airstrikes.
State TV said two people were wounded in IS shelling on the nearby town of Salamiyeh.
The IS-linked Aamaq news agency confirmed an attack is ongoing in the area without giving details.