At least 100,000 Syrian refugees flooded across the border into Turkey over the weekend as Sunni extremist fighters from the Islamic State of Iraq and Greater Syria (ISIS) launched an offensive against Kurdish communities in northern Syria.
Approximately 150,000 people have been displaced since ISIS began to encircle the border town of Kobani, also known as Ayn al-Arab, last week.
“Four or five days ago this area was quite safe,” Selin Unal, a spokesperson with the U.N.’s refugee agency, the UNHCR, told TIME on Monday. “And then after three days, 100,000 Syrians fled to Turkey.”
The militants have reportedly routed dozens of towns and executed at least 11 people in the villages outside of Kobani, according to activists.
“[ISIS] are continuing to advance,” Welat Avar, a doctor, told Reuters from Kobani. “Every place they pass through they kill, wound and kidnap people. Many people are missing and we believe they were kidnapped.”
International aid groups and Turkish officials warned that thousands of additional refugees are likely to try to cross the border in the coming days amid the militants’ offensive. Before the weekend’s onslaught, Turkey had already been home to close to 1.5 million refugees from the conflict-torn nation.
“Turkish government authorities and UNHCR are preparing for the possibility of hundreds of thousands more refugees arriving over the coming days, as the battle for the northern Syrian city of Kobani forces more people to flee,” read a statement released by the U.N. refugee agency over the weekend.
On Sunday, the Kurdistan Workers’ Party (PKK), a group classified as a terrorist organization by both Ankara and Washington, called on fellow Kurds to take up arms to repel ISIS.
“Supporting this heroic resistance is not just a debt of honor of the Kurds but all Middle East people. Just giving support is not enough, the criterion must be taking part in the resistance,” the PKK said in a statement.
The British-based Syrian Observatory for Human Rights reported that hundreds of Kurdish fighters from inside Turkey crossed into Syria over the weekend to help beat back the ISIS offensive. Near the border, Turkish Kurds demonstrated in solidarity with the refugees, leading to clashes with authorities, who deployed tear gas and water cannon against the protesters.
While ISIS’s thrust in Iraq has been largely slowed by U.S. air strikes, American forces have yet to target the militant group’s myriad positions in neighboring Syria, thus allowing the group to continue to consume large swaths of territory across the country’s north and east.
During an interview on CBS’s Face the Nation on Sunday, U.S. Ambassador to the U.N. Samantha Power hinted that the White House and its allies are ready to strike in Syria, but refrained from announcing how the Obama Administration was preparing to do so.
“The President has said we’re not going to allow [ISIS] to have a safe haven in Syria,” said Power. “But no decisions have been made in terms of how we’re going to proceed in that.”
Earlier this month, Turkey refrained from joining the U.S.-led coalition aiming to take the fight to the jihadist organization.
The uptick in violence along Turkey’s frontier coincides with the release of 49 Turkish diplomats over the weekend. All 49 had been in ISIS’s custody for three months since jihadist militants routed Iraqi security forces in Mosul in July.
Ankara has yet to provide firm details regarding the so-called rescue operation that succeeded in freeing the diplomats.