Turkish jets pounded Kurdish militia targets Saturday in the Syrian town of Afrin in an attempt to oust the fighters, Turkey's state-run news reported.
The move is likely to sharpen tensions between Turkey and the United States, which supports and openly arms Kurdish militias fighting ISIS. A new operation targeting Kurdish fighters could open up a new frontier in the Syrian conflict, which has gone on for nearly seven years.
Ankara has long fought Kurdish unrest in southeastern Turkey. It's determined to prevent the establishment of a Kurdish state across the border in Syria and has used military force in the past against Kurds and ISIS in the northern part of the neighboring country.
Afrin is under the control of the People's Protection Units -- the largely Kurdish militia known as the YPG that Turkey regards as a terror group.
In Saturday's assault, explosions were heard as jets swooped over Afrin, and Turkish-backed rebels from the Free Syrian Army began entering the town, according to Anadolu Agency, Turkey's state-run outlet.
Residents and activists also reported airstrikes in the region. The Turkish armed forces said that 108 out of 113 targets had been hit and that all of the dead and wounded brought to hospitals are Kurdish militia members.
Turkish Foreign Affairs Minister Mevlut Cavusoglu said in a tweet that the operation isn't targeting civilians and "innocent Syrians" -- just terrorists.
Earlier Saturday, Turkish President Recep Tayyip Erdogan said the military offensive is in its early phase. He said forces will next move on the Syrian town of Manbij farther east on the Turkish border.
"We know that without security in Syria, there cannot be security in Turkey," Erdogan told members of his ruling party in Kutahya.
Report: Russia to back Syria at UNWashington has been concerned about a Turkish military incursion and called on Ankara to refrain from launching one. "The focus needs to be on ISIS," State Department spokeswoman Heather Nauert said this week.
Turkish forces said they are targeting ISIS as well as Kurdish militia in Afrin in an undertaking called Operation Olive Branch.
"The operation is being carried out within the right of self-defense and with respect to Syrian territorial integrity," the armed forces said in a statement.
The Turkish Foreign Ministry is briefing the heads of missions of the United States, Russia and Iran in Turkey on the latest developments in Afrin, Anadolu reported.
Russia will back the Syrian government diplomatically and support a demand at the United Nations for Turkey to stop its military operation, state-run RIA Novosti quoted a senior lawmaker as saying.
"At the United Nations, not only Syria will demand the termination of this operation, Russia will support these demands and will provide Syria with diplomatic assistance," said the lawmaker, Franz Klintsevich.
The Russian Foreign Ministry called for restraint Saturday. Its Defense Ministry said it had relocated some troops out of the Afrin area "to prevent possible provocations and to exclude the possibility of the threat to the life and health of Russian servicemen."
Turkish incursion had been expected in AfrinTurkish-backed fighters from the Free Syrian Army were battling Kurdish militia members recently in Afrin, and a full cross-border Turkish military incursion had been expected.
More than 50 Turkish vehicles, including artillery, tanks, rocket launchers and heavy equipment transporters, had been observed on the Turkish-Syrian border, a US defense official said Friday.
Turkish state-run media suggested that the new operation would involve airstrikes from warplanes and drones, and that Turkish-trained militia from the Free Syrian Army alliance would be first on the ground in any land offensives.
US-trained border force in ManbijManbij is in an area where a 30,000-strong US-trained border force from the Syrian Democratic Forces, dominated by YPG fighters, is to be trained. Turkish-backed rebels and US forces have been trading fire there, US defense officials said.
The announcement of a border force infuriated Turkey's leaders, and Erdogan has accused the United States, its most powerful NATO ally, of "building an army of terror" on his border and threatened to "drown" the US-backed force.
Turkey regards the YPG as the Syrian arm of the Kurdistan Workers' Party, or PKK, despite the group's help in battling ISIS.
The PKK is an outlawed Kurdish group responsible for major terror attacks in Turkey as part of its bid for national ethnic autonomy. The European Union and United States have both named the PKK as a terrorist outfit.
"By changing the name of a terrorist organization that is playing games in Syria, they think (they) are being smart. Who do you think you are fooling? The name of this organization is PKK, PYD, YPG," Erdogan said Saturday.
"No matter what they say, we don't care anymore because we look at what is happening in the field."