Kurdish and Arab fighters have abandoned the U.S.-backed fight against the Islamic State (ISIS/ISIL) to help their friends and families repel a Turkish offensive reportedly assisted by Syrian rebels seeking to take revenge on the Kurds.

“We’re preparing to head to Afrin,” Roshavam Qamishlo, a fighter from the Syrian Democratic Forces (SDF), told the Agence France-Presse (AFP) agency on Saturday. The enclave “needs us now more than ever.”

The U.S.-backed SDF, an Arab-Kurdish alliance primarily made up and led by the People’s Protection Units (YPG), recently deployed 1,700 mainly Arab fighters to join their Kurdish allies in Afrin as Turkey claimed to have conquered “nearly half” of the region.

YPG fighters are the armed wing of the Kurdish Democratic Union Party (PYD), which controls swaths of northern Syria and has declared autonomy in that region, something that the Russian and Iranian-backed Assad has indicated he may be open to as long as the Kurds remain part of Syria.

Citing the U.K.-based Syrian Observatory for Human Rights (SOHR), which monitors the conflict using a network of sources on the ground, AFP places the number of civilian deaths since the Turkey-led operation in Afrin started on January 20 at more than 170.

Meanwhile, the state-owned Syrian Arab News Agency (SANA) claims Turkish troops and their allies have killed or wounded “up to 900 civilians.”

The Turkish military claims to have “neutralized” an estimated “3,055 People’s Protection Units (YPG)” in the ongoing operation in northern Syria’s Afrin region.

Turkey has called its NATO ally, the United States, to prevent fighters from the U.S.-allied YPG from moving into Afrin, Reuters learned from a spokesman for the Turkish president.

However, while the United States maintains it has no “direct relationship” with the YPG in Afrin, it has not stopped it from assisting its friend and families fighting against Turkey and its Syrian rebel allies, which include the Free Syrian Army (FSA), which has received American taxpayer-funded assistance in the past.

The United States has urged Turkey to halt its offensive in Afrin, noting that it is having a negative impact on the fight against ISIS.

Some experts, including former U.S. Amb. Ryan Crocker, have warned that America’s reluctance to assist the Kurds in Afrin will drive them to join the Iran, Russia, Syria coalition.

Turkey has long considered the YPG an extension of the Kurdistan Workers’ Party (PKK), which both Washington and Ankara deem a terrorist organization.

However, the United States has continued to assist the YPG, which various American officials have described as an effective partner against ISIS.

Some Syrian rebels have joined Turkey’s side to take revenge on the Kurds, reports the Washington Post (WaPo), noting:

Syrian rebels who have joined Turkey’s cross-border offensive against a Kurdish enclave say they see the assault as a way to settle personal scores, and reports are mounting of looting and summary executions carried out by the Syrian fighters.

Backed by Turkish troops and warplanes, thousands of Syrian rebels are now tightening their grip on the Kurdish-controlled Afrin enclave in northern Syria as part of an offensive that Turkey has framed as a matter of its national security.

At home, Turkey has been fighting against Kurds closely allied with the YPG for decades.

Since the civil war began in Syria in 2011, Assad troops and their Iranian and Russian allies have been fighting Turkey-assisted rebels, whom the dictator considers terrorists.

Now, the Turks and their Syrian rebel allies are facing off against the Kurds, their Arab partners, and pro-Assad fighters.

Citing various media reports, Breitbart News reported last month that “hundreds” of Iranian-allied Shiite troops loyal to Assad had joined the U.S.-allied YPG and their partners in Afrin to repel the Turkish offensive.

Referring to a recent battle, Al-Monitor reports:

That first armed confrontation between the [Turkish Armed Forces] TSK and pro-Assad militias in northern Syria is cause for serious concern, especially for Moscow, because if the fight escalates to clashes between TSK and Assad’s army — rather than just supporting militias — it could mean the collapse of de-escalation efforts west of the Euphrates.

Moscow’s vision for northern Syria is clear. On one side of the negotiation table, Assad will sit as the big brother under Russian wings with the Democratic Union Party [PYD] as the younger brother representing the Syrian Kurds, who must be pro-Russia, staunchly secular and leftist. On the other side of the table facing them will be the Syrian opposition, under the tutelage and control of Ankara.

Although Turkey supports anti-Assad rebels, tensions with the United States have driven Ankara closer to Moscow.