Turkish forces have bombed a detention centre housing thousands of families linked to ISIS, Syrian-Kurdish militias said on Monday, alleging that many could now escape.
The attack came as Turkey's President Recep Tayyip Erdogan said he would be open to meeting Syria's President Bashar Al Assad to discuss resolving the crisis, six days into a Turkish military operation in Syria and northern Iraq.
The Syrian Democratic Forces (SDF) have long appealed for international help in running Al Hol and repatriating extremists. They said Thursday's strike had already allowed some people inside the camp to escape.
The Syrian Observatory for Human Rights, a war monitor, said a warplane had struck an SDF position outside the camp, but there were conflicting accounts of how many bombs had struck the area.
The attack occurred as the Turkish military campaign in Syria and northern Iraq continued, aimed at Kurdish militias including the Kurdistan Workers Party (PKK), which is largely based in southern Turkey and northern Iraq, and the SDF. The operation was launched in response to a November 13 bombing in Istanbul, which killed six people, including two children.
Turkey blamed the SDF and PKK and said the operation was planned on Syrian soil.
The PKK are designated as a terror group by the US and EU, while the SDF has received support from the West in the war on ISIS, while also co-ordinating with Mr Al Assad's government.
Mr Erdogan has given a warning that the campaign will continue with further ground incursions — beyond land already controlled by Turkish troops and allied Syrian militias.
“Our operations that we are carrying out with planes, artillery and guns are just the beginning," the Turkish leader said on Wednesday. "Our determination to close down all of our southern borders, from Hatay to Hakkari, with a security strip that will prevent the possibility of attacks on our country is stronger than ever," he said.
Mr Erdogan also said on Wednesday he was open to meeting Mr Al Assad, telling reporters "there can be no resentment in politics."
Mr Al Assad is strongly opposed to the Turkish presence on Syrian soil, which includes Islamist militia groups trained and funded by Ankara, occupying parts of northern provinces including districts in Aleppo, Raqqa and Hassakeh. A number of Syrian soldiers have been killed in Turkey's recent offensive.
Turkey regularly conducts air strikes against Kurdish groups in Iraq and Syria. Some of the raids have killed civilians and emptied residential areas, prompting condemnation from Iraqi and Syrian authorities.
'Chaos' in ISIS-linked camp
ISIS-linked women reportedly escaped a Syrian refugee camp on Wednesday after the Turkish air strikes.
A representative of the SDF said several residents were able to escape after the camp's security was hit in a Turkish attack. They were later arrested.
Farhad Shami said the camp was still under threat of further attack with Turkish reconnaissance aircraft hovering over the site.
The Observatory said "chaos" broke out after two Turkish strikes hit the edge of the camp, while local Kurdish media outlets reported three.
The SDF, which works closely with the US-led coalition, has been key in territorially defeating ISIS in Syria, where the group still conducts insurgent attacks.
Turkish strikes "jeopardise the safety of civilians, fracture the hard-fought stability within the region and disrupt our common goal of defeating ISIS," the coalition said on Tuesday.
Kurdish authorities who control Al Hol are regularly attacked by camp residents, and some have been killed. The Kurds and the international community have repeatedly given warnings that the camp is a security burden and breeding ground for future extremism.
Other areas in the Hassakeh region were hit on Wednesday, including key oilfields. Turkish air strikes have also hit Kurdish camps in Russian and coalition bases.
Moscow, a staunch ally of Damascus, has urged Ankara not to conduct a full-scale invasion of the north-east in an attempt to expand its so-called safety corridor.