BEIRUT -- France and the United States on Tuesday urged Turkey to exercise restraint in its offensive against a Kurdish-held enclave in northern Syria, where the UN says an estimated 5,000 people have been displaced by the fighting.
Turkish troops and allied Syrian fighters pressed ahead with their operations in Afrin for the fourth day, approaching from three sides and meeting stiff resistance from the U.S.-allied Kurdish militia that controls the enclave.
The UN said most of the displaced are still inside Afrin because Kurdish forces are preventing civilians from leaving and Syrian government forces are keeping them out of adjacent areas. International aid groups have no presence in Afrin, which is surrounded by Turkey and rival Syrian forces.
On Tuesday, the Kurdish militia, known as the People's Defence Units or YPG, regained control of a village breached by Turkish forces. The Turkish forces were also repelled from a hill they seized a day earlier on the eastern edge of the district.
The YPG is a key U.S. ally against IS and played a major role in driving the extremists from much of northern and eastern Syria. The U.S. military operates bases in Kurdish-controlled territory in northern Syria but not in or near Afrin.
Ankara views the YPG as a threat because of its links to the decades-old Kurdish insurgency in Turkey. Turkey says it aims to create a 30-kilometre (20-mile) deep "secure zone" in Afrin, which is in northwestern Syria near the border.
France's Foreign Minister Jean-Yves Le Drian said the intense fighting in recent days is a sign that new conflicts could erupt in the region as the IS group is defeated.
He warned that without a political solution to the multi-sided Syrian civil war, the region could again explode, with conflicts "just as dramatic" as the war on IS.
French President Emmanuel Macron spoke Tuesday with Turkish President Recep Tayyip Erdogan, expressing his concern about the operation, according to a statement from Macron's office.
He stressed the importance of seeking a lasting political solution for Syria alongside fighting IS and ensuring the delivery of humanitarian aid.
U.S. Defence Secretary Jim Mattis, who is currently travelling in Asia, said the fighting "disrupts what was a relatively stable area of Syria" and "distracts from the international efforts to ensure the defeat of ISIS," using another acronym for IS.
Gen. Joseph Votel, the head of the U.S. Central Command, and Brett McGurk, the White House envoy for the war against IS, have been in eastern Syria since Monday, meeting with Kurdish officials and discussing Afrin and other issues.
At least 27 civilians, including eight children and four women, have been killed in the fighting in Afrin, mainly in Turkish airstrikes, according to the Syrian Observatory for Human Rights, a Britain-based group that monitors the civil war.
At least three Turkish soldiers have been killed since the offensive began Saturday and at least one civilian was killed in Turkey by cross-border shelling. The Observatory said 38 Kurdish fighters and 43 Turkish-backed Syrian militiamen have been killed.
Meanwhile, Turkish police have detained at least 55 people in a sweep against alleged supporters of the YPG inside Turkey, according to the state-run Anadolu Agency.
Turkey also shelled a city in northeastern Syria, hundreds of miles away from Afrin, according to the YPG.
Nureddine Mehmud said Turkey fired on Qamishli and other towns along the border on Tuesday, calling it a diversion from the main campaign in Afrin. There were no reported casualties.
Mehmud said the YPG and allied militias had managed to prevent the Turkish forces from making "any real progress" in Afrin.
The UN says at least 323,000 people reside in Afrin, nearly half of whom have fled from other parts of Syria. Local officials put the number at 800,000.
Rezan Hiddo, a Kurdish official in Afrin, said people are seeking shelter wherever they can find it.
"The strikes are from aircraft, rocket launchers and artillery," he said. "This is causing townspeople to take cover in basements. People in the villages are hiding in their farms, while those in the mountains are taking cover in caves for protection."
Hiddo said since 2012, when Afrin came under the control of the YPG, the town has suffered varying degrees of siege, first by opposition fighters, then IS militants, and now at the hands of the Turkish-led forces.
"The Turkish army is besieging Afrin from three sides," Hiddo said. "There is only one narrow corridor that links it to Aleppo. The area suffers from lack and shortage of supplies."
The Syrian conflict began as a popular uprising against the Assad family's four-decade rule but escalated into a civil war following a fierce government crackdown and the rise of an insurgency. At least 400,000 people have been killed and half the country's population has been displaced by the war.
Associated Press writer Zeynep Bilginsoy in Istanbul contributed to this report.