At least 750 people with suspected links to Islamic State have reportedly fled a displacement camp in north-east Syria, local officials have said, raising fears that the Turkish offensive against Kurdish forces in the area could lead Isis to regain strength amid the chaos.

The news came at the same time the US ordered all 1,000 US troops to withdraw “as safely and quickly as possible” from the region after learning that the Turkish operation was likely to extend further than Ankara’s proposed 20-mile (32km) “safe zone” on the border between the two countries.

The bloody conflict between Turkey and the formerly US-backed Syrian Democratic Forces (SDF) fighters “gets worse by the hour”, the US defence secretary, Mark Esper, said on Sunday in a pre-taped interview.

While US forces made preparations to pull out, the mayhem in Kurdish-held north-east Syria intensified, with reports that Turkish backed militias had summarily executed several civilians, including a female Kurdish politician.

On Sunday night Syrian TV said government troops were moving to the north to confront the Turkish offensive, potentially setting up direct clashes between Turkey and the Assad regime.

The 249 women and 700 children formerly part of the “caliphate” were held in a secure annexe at the Ain Issa camp. They began to riot and scared away the guards after Turkish shelling struck close to the area on Sunday, Abdulkader Mwahed, the joint president for humanitarian affairs in the Kurdish-held part of Syria, said in a statement.

Jelal Ayaf, the co-chair of the camp’s management, said sleeper cells within the civilian section also emerged during the riot, attacking the remaining guards who had not already fled the shelling.

Quick guide What is happening in north-eastern Syria? Show Hide Who is in control in north-eastern Syria? Until Turkey launched its offensive there on 9 October, the region was controlled by the Syrian Democratic Forces (SDF), which comprises militia groups representing a range of ethnicities, though its backbone is Kurdish. Since the Turkish incursion, the SDF has lost much of its territory and appears to be losing its grip on key cities. On 13 October, Kurdish leaders agreed to allow Syrian regime forces to enter some cities to protect them from being captured by Turkey and its allies. The deal effectively hands over control of huge swathes of the region to Damascus. That leaves north-eastern Syria divided between Syrian regime forces, Syrian opposition militia and their Turkish allies, and areas still held by the SDF – for now. On 17 October Turkish president, Recep Tayyip Erdoğan, agreed with US vice-president Mike Pence, to suspend Ankara’s operation for five days in order to allow Kurdish troops to withdraw. The following week, on 22 October, Erdoğan and his Russian counterpart, Vladimir Putin agreed on the parameters of the proposed Turkish “safe zone” in Syria. How did the SDF come to control the region? Before the SDF was formed in 2015, the Kurds had created their own militias who mobilised during the Syrian civil war to defend Kurdish cities and villages and carve out what they hoped would eventually at least become a semi-autonomous province. In late 2014, the Kurds were struggling to fend off an Islamic State siege of Kobane, a major city under their control. With US support, including arms and airstrikes, the Kurds managed to beat back Isis and went on to win a string of victories against the radical militant group. Along the way the fighters absorbed non-Kurdish groups, changed their name to the SDF and grew to include 60,000 soldiers. Why does Turkey oppose the Kurds? For years, Turkey has watched the growing ties between the US and SDF with alarm. Significant numbers of the Kurds in the SDF were also members of the People’s Protection Units (YPG), an offshoot of the Kurdistan Workers’ party (PKK) that has fought an insurgency against the Turkish state for more than 35 years in which as many as 40,000 people have died. The PKK initially called for independence and now demands greater autonomy for Kurds inside Turkey. Turkey claims the PKK has continued to wage war on the Turkish state, even as it has assisted in the fight against Isis. The PKK is listed as a terrorist group by Turkey, the US, the UK, Nato and others and this has proved awkward for the US and its allies, who have chosen to downplay the SDF’s links to the PKK, preferring to focus on their shared objective of defeating Isis. What are Turkey’s objectives on its southern border? Turkey aims firstly to push the SDF away from its border, creating a 20-mile (32km) buffer zone that would have been jointly patrolled by Turkish and US troops until Trump’s recent announcement that American soldiers would withdraw from the region. Erdoğan has also said he would seek to relocate more than 1 million Syrian refugees in this “safe zone”, both removing them from his country (where their presence has started to create a backlash) and complicating the demographic mix in what he fears could become an autonomous Kurdish state on his border. How would a Turkish incursion impact on Isis? Nearly 11,000 Isis fighters, including almost 2,000 foreigners, and tens of thousands of their wives and children, are being held in detention camps and hastily fortified prisons across north-eastern Syria. SDF leaders have warned they cannot guarantee the security of these prisoners if they are forced to redeploy their forces to the frontlines of a war against Turkey. They also fear Isis could use the chaos of war to mount attacks to free their fighters or reclaim territory.

On 11 October, it was reported that at least five detained Isis fighters had escaped a prison in the region. Two days later, 750 foreign women affiliated to Isis and their children managed to break out of a secure annex in the Ain Issa camp for displaced people, according to SDF officials. It is unclear which detention sites the SDF still controls and the status of the prisoners inside. Michael Safi

The UK-based monitor the Syrian Observatory for Human Rights put the number to have escaped at 100, publishing pictures of men, women in black niqabs and small children running through yellow scrubland. It was not clear whether the pictures showed Isis families or civilian residents of the camp fleeing the Turkish attack. No Isis men were held at the facility.

Save the Children’s staff members on the ground reported no foreign women were left at the camp and that masked men on motorbikes were circling the perimeter.

The camp was home to a total of about 13,000 people, including three suspected British orphans and a notorious British recruiter for Isis, Tooba Gondal.

Turkey launched an offensive against the Kurdish-led SDF over its southern border on Wednesday, a move widely condemned by the international community for triggering a humanitarian disaster, opening a new front in Syria’s complex war and risking the re-emergence of Isis, which lost control of its final slivers of territory in March.

Operation Peace Spring, as Ankara has designated it, was triggered by Donald Trump’s decision to withdraw US troops partnered with the SDF from the region last week. The US special forces have long acted as a buffer stopping the SDF and Turkey from clashing: Ankara considers the Kurdish YPG, which makes up the majority of the multi-ethnic SDF, as a terrorist group indistinguishable from the outlawed militant group the Kurdistan Workers’ party (PKK). Trump has denied the decision to abandon the SDF to a likely attack from Turkey was a betrayal.

Trump, in a tweet on Sunday, said: “Very smart not to be involved in the intense fighting along the Turkish Border, for a change. Those that mistakenly got us into the Middle East Wars are still pushing to fight. They have no idea what a bad decision they have made. Why are they not asking for a Declaration of War?”

The Turkish president Recep Tayyip Erdoğan’s stated goal is to create a “safe zone” 20 miles deep on its border with the SDF, deep enough to keep Turkish border towns out of the range of shelling and rocket fire.

Play Video 4:04 What does Turkey's military action in northern Syria mean? – video explainer

However, Ain Issa and other Kurdish-held roads and towns south of the proposed safe zone have been hit by airstrikes and shelling. On Sunday morning Syrian rebels allied to the Turks were advancing south on the town of Ain Issa, two military sources told the Guardian.

Speaking on Sunday, Erdoğan rejected offers for mediation with the SDF and criticised his western Nato allies for standing by what Turkey considers to be a terrorist organisation.

“What kind of prime minister, what kind of head of state are those who offer to mediate between us and the terror group?” the president asked, without specifying which countries made a mediation offer.

He also dismissed the reports of escaped Isis prisoners as “disinformation” aimed at provoking the US and other western countries.

About 130,000 people have been displaced in Syria in the five-day-old operation so far.

The Kurdish Red Crescent, a local NGO not affiliated with the International Committe of the Red Cross, said 14 civilians have died, with another 46 seriously injured as a result of the offensive to date. Nine people, including a Syrian baby, have been killed in counterattack SDF shelling of Turkish border towns.