BEIRUT — Turkish jets and artillery struck U.S.-backed Syrian Kurdish fighters in northern Syria on Thursday, and Turkey's state-run news agency said as many as 200 militiamen were killed in a major escalation of Turkey's offensive in northern Syria.
A senior commander with the main Syria Kurdish militia confirmed the Turkish attack on his forces north of Aleppo, but disputed the casualty toll, saying that no more than 10 fighters had been killed so far.
Further south, in the rebel-held city of Aleppo which has been besieged by pro-government troops, a humanitarian pause announced by Russia took effect on Thursday.
Senior U.N. aid official Jan Egeland told The Associated Press that the U.N. received verbal assurances for the extension of the three-day pause by another day until Monday to allow for U.N. supervised medical evacuation of wounded from inside the city.
Russia's Defense Minister Sergei Shoigu confirmed an extension but only mentioned the pause was being prolonged by one more day. The discrepancy between his and Egeland's statements could not immediately be reconciled.
So far, there were no sign of residents taking up the offer of safe passages. Clashes were heard at one of the corridors advertised by the Syrian military. Using loudspeakers, the military urged residents to evacuate and gunmen to lay down their weapons.
"The battle for returning Aleppo to the nation's fold is in its last phases. There is no point in continuing the fight," echoed from a checkpoint between government-held and rebel-held Aleppo.
U.N Syria envoy Staffan de Mistura insisted a unilateral cease-fire aims only to allow medical evacuations and is not part of a broader plan that he has laid out for the besieged northern city, countering the Syrian President Bashar Assad's claim that most civilians want to leave.
Also, German Chancellor Angela Merkel pressed anew for a long-term cease-fire in the Syrian city of Aleppo while British Prime Minister Theresa May urged European Union partners to unite in condemnation of Russia's role in Syria and bring an end to Moscow's "sickening atrocities" there.
Even as the city of Aleppo enjoyed a relative lull, Turkey escalated its bombing in the Aleppo province, striking Kurdish-led.
As in Iraq where the Kurdish fighters are at the forefront of the offensive to retake the city of Mosul, Kurdish forces in Syria have also been battling the Islamic State group and have made significant territorial gains, including advances in the last few days against IS militants in Aleppo province, upsetting Ankara. Turkey, which is dealing with a homegrown Kurdish insurgency, has been trying to prevent an expansion of Kurdish influence in Syria.
"We will not back down," Kurdish commander Mahmoud Barkhadan of the People's Protection Units told The Associated Press. "We are fighting Daesh, why are they striking at us?" he asked, using the Arabic acronym for IS.
He was speaking in a telephone interview from the area. He accused Turkey of aiding IS militants by diverting the fight into a Turkish-Kurdish one.
He said Turkish tanks have been shelling the Kurdish-led forces in the area since early Wednesday. He said jets joined overnight and continue to pound his forces. He said more than 30 aerial attacks had taken place so far and that early reports suggest no more than 10 fighters were killed and 20 were wounded. There was no word on civilian casualties yet. The Britain-based Syrian Observatory for Human Rights said at least 11 Kurdish fighters were killed and four are missing.
Barkhadan, a senior commander who led the fight against IS in Kobani in 2015, said Turkish artillery also shelled an area near Afrin, a Kurdish enclave in northwestern Syria. He said his forces have not retreated from newly held territories, but that the Turkish attack allowed IS fighters to wage a counteroffensive. Clashes continued Thursday, the Observatory and Barkhadan said.
The Anadolu Agency, quoting military officials, said the raids were carried out late Wednesday night, attacking 18 targets in the Maarraat Umm Hawsh region in northern Syria. The agency claimed that 160 and 200 militia fighters were killed in the raids. The targets hit were in areas that the Syrian forces recently took over as they pressed ahead with their campaign to drive Islamic State militants from areas north of Aleppo.
The Syrian Kurdish forces have been a source of tension between NATO allies Turkey and the United States. The U.S. considers the militia group — the People's Protection Units or YPG — to be the most effective force in the fight against the Islamic State group in Syria. Turkey says it's an extension of its own outlawed Kurdish militants who have carried out a series of deadly attacks in Turkey in the past and considers it to be a terrorist organization.
In August, Turkey sent troops and tanks into northern Syria to help Syrian opposition forces drive the Islamic State group away from an area bordering Turkey, and to curb the Syrian Kurdish forces' territorial expansion.
A senior Syrian Kurdish official said the Turkish attack was an aggression on her people's aspiration for self-administration a contiguous territory in the country's north as well as a threat to the U.S-led anti-terrorism fight there.
Ilham Ahmed said Turkish maneuvering threatens a possible campaign against IS in the group's de-facto capital of Raqqa in eastern Syria. Kurdish forces are the main partner in such a fight, but Ankara recently has said it is ready to take part without Kurdish participation. She said Ankara is taking advantage of U.S. focus on its upcoming elections to push back the Kurds and advance in Aleppo.
Washington is "asked to put a stop and take a clear and direct position regarding this Turkish aggression. Otherwise the project of combatting terrorism may be delayed or totally fail in Syria," she said speaking from Sulaimaniyah, Iraq.
Anadolu said the 18 Syrian Kurdish targets hit included nine buildings used as headquarters, meetings points, shelters or arms depots as well as five vehicles.
For Aleppo, Moscow had said the humanitarian pause is to allow civilians and militants safe passage out of the eastern districts of the city — which have been subjected to a tight siege since July and a punishing bombing campaign since mid-September.
Egeland, the U.N top aid official, said talks are still ongoing with armed opposition groups on the implementation of the deal, describing as "complicated" details of the checkpoints. He said he expects medical supplies to be allowed in.
Ibrahim al-Haj, a resident of eastern Aleppo and a volunteer with the White Helmets, a team of first responders in the besieged city, said no one trust safe passages without U.N. supervisions.
"If there is no corridor with international supervision, it is impossible anyone would leave," said al-Haj, adding shots were fired over the heads of some who approached the crossing Thursday, accusing government snipers.