BEIRUT -- Turkey escalated its offensive Thursday against Kurdish fighters in northern Syria, pounding them with airstrikes and artillery and complicating the battle against the Islamic State extremist group by Ankara and Washington, both NATO allies.
Turkey's state-run Anadolu news agency said as many as 200 members of the Kurdish-led forces were killed in Syria's Aleppo province by the Turkish bombing and shelling.
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 were killed.
In the fight for Aleppo, meanwhile, the Syrian military used a lull in violence to urge residents and rebels to evacuate the besieged opposition-held part of the city.
As in Iraq, where Kurdish fighters are at the forefront of the offensive to retake the city of Mosul from the Islamic State, Kurdish forces in Syria also have been battling Islamic State militants and made significant territorial gains in Aleppo province. That has dismayed Turkey, which is dealing with an internal Kurdish insurgency and trying to prevent an expansion of Kurdish influence in Syria.
"We will not back down," senior Kurdish commander Mahmoud Barkhadan of the People's Protection Units said by telephone from the region.
"We are fighting Daesh. Why are they striking at us?" he asked, using an Arabic acronym for the Islamic State.
Barkhadan accused Turkey of aiding Islamic State militants by turning the fight into a Turkish-Kurdish battle.
More than 10 fighters were killed and 20 wounded in over 30 aerial attacks that began Wednesday night, he said.
The Britain-based Syrian Observatory for Human Rights said at least 14 Kurdish fighters were killed and four were missing.
Anadolu, quoting military officials, reported the raids were carried out late Wednesday on 18 targets in the Maarraat Umm Hawsh region in northern Syria. Between 160 and 200 militia fighters were killed, it said. The targets struck areas that Syrian Kurdish forces recently took over as they pressed a campaign to drive Islamic State militants from areas north of Aleppo.
The Syrian Kurdish forces have been a source of tension between Turkey and the United States. The U.S. considers the militia group -- the People's Protection Units -- to be the most effective force against the Islamic State in Syria. Turkey calls it an extension of its own outlawed Kurdish militants who have carried out deadly attacks in Turkey and considers it a terrorist organization.
A U.S. defense official in Washington said the Syrian Kurdish fighters targeted by Turkish airstrikes Wednesday are not among the Kurdish groups that U.S. forces are advising and assisting, so there were no U.S. troops with those Kurds when they came under attack.
Ilham Ahmed, a senior Syrian Kurdish official, said the Turkish attack was an aggression on her people's aspiration for self-administration in a contiguous territory in the north as well as a threat to the U.S-led anti-terrorism fight there.
The Turkish moves threaten a campaign against the Islamic State in the group's de-facto capital of Raqqa in eastern Syria, Ahmed said. Kurdish forces are the main partner in such a fight, but Turkey has said it is ready to act without Kurdish participation.
Ahmed said Turkey is taking advantage of U.S. attention being focused on its presidential election to push back against the Kurds and advance in northern Syria.
The U.S. is "asked to put a stop and take a clear and direct position regarding this Turkish aggression. Otherwise, the project of combating terrorism may be delayed or totally fail in Syria," she said, speaking from Sulaimaniyah, Iraq.
Aleppo pause
The pause in the fighting in Aleppo is part of a humanitarian cease-fire announced by Russia in the contested city to allow for the evacuation of civilians and fighters, as well as the wounded. Rebels have rejected the offer to evacuate, saying it wasn't serious.
Clashes were heard at one of the safe corridors announced by the Syrian military.
"Talk of fighters or nonfighters leaving is denied and groundless," said Ammar Sakkar, spokesman for Fastaqim, one of the largest rebel groups operating in Aleppo. "The rebels' decision has not and will not change. It is to be steadfast."
Helicopters dropped hundreds of thousands of leaflets on Aleppo urging rebel fighters to take advantage of the amnesty and leave the city through safe exits marked on maps, according to state-run Syrian TV.
Syria's military used loudspeakers Thursday to urge residents in opposition areas to stop fighting, The Associated Press said, reporting that one repeated message blared: "The battle for returning Aleppo to the nation's fold is in its last phases. There is no point in continuing the fight."
"We don't trust them," said Abu al-Hasan, a commander of a Fastaqim unit in Aleppo, referring to Russia and the Syrian government. "They always talk about cease-fires and truces, but what they do is constantly target civilians and violate the laws of war."
Eastern Aleppo, besieged by government troops, has been subjected to intense and relentless airstrikes by Syrian and Russian aircraft in recent weeks. Hundreds of people have been killed and whole neighborhoods destroyed.
U.N. Syria envoy Staffan de Mistura insisted that a unilateral cease-fire aims only to allow medical evacuations and is not part of a broader plan he has laid out for Aleppo, countering an assertion by Syrian President Bashar Assad that most civilians want to leave.
Senior U.N. aid official Jan Egeland said the U.N. received verbal assurances for the extension of the three-day pause by another day until Monday to allow for the U.N.-supervised medical evacuation of wounded from the city.
Russian Defense Minister Sergei Shoigu confirmed an extension but only mentioned the pause was being prolonged by one day. The discrepancy between the statements could not immediately be reconciled.
The United Nations and aid agencies have not rushed to get aid to the besieged residents, saying the pause provided insufficient time and guarantees from forces allied with Assad.
But speaking from Geneva on Thursday, Egeland said Syria's government has given "green lights" to deliver aid to besieged areas of Aleppo. He held out hope for U.N.-supported evacuations of several hundred wounded and sick people.
Information for this article was contributed by Sarah El Deeb, Suzan Fraser, Jamey Keaten, Robert Burns and Vladimir Isachenkov of The Associated Press; by Donna Abu-Nasr of Bloomberg News; and by Hugh Naylor, Zakaria Zakaria and Brian Murphy of The Washington Post.
A Section on 10/21/2016