When the first shell thudded to earth, the people of Ras al-Ayn were ready. So long had the buildup been – and so heated the warnings – that those who fled the opening salvos of Turkey’s offensive in Kurdish northern Syria did so with little panic.

On tractors, horses, in cars and on motorbikes, the region’s newest refugees made their way from the border town that had been long pinpointed as the starting point of a Turkish invasion.

Turkish jets took off from runways just to the north, sending missiles streaking through the sky and into one of the town’s few high-rise buildings. By sunset, around 15 shells had landed in Ras al-Ayn, according to local official, Hevin Darwiche.

As night drew near, new fears began to mount; might darkness bring a ground offensive that would send proxy forces trained by Ankara to retake the predominantly Arab town from the Kurds?

Play Video 0:35 Explosions hit Syrian town of Ras al-Ayn on Turkish border – video

Such are the contradictions of the Turkish operation: Kurdish forces that only months ago were fighting alongside the US military against Isis were now about to be attacked with the US president’s explicit permission. Furthermore, many of Turkey’s Arab proxy forces were former US allies several years ago, raised to fight the Syrian regime before Washington lost interest.

Nearby, French forces garrisoned close to the border also began to leave the area, according to local reports and regional diplomats. Their raison d’etre had been to defeat the Islamic Stateterror group, the remnants of which remain detained in four camps – two of which were volatile and tense ahead of the Turkish push.

Isis has been contained but, as European diplomats warned this week, continues to pose a lethal threat to global security.

What is the situation in north-eastern Syria? Read more

Now would not be an ideal time to leave – were it not for the fact that US forces had abandoned the province first. Without any of their friends standing in the way of the Turks, the Kurds would have to do the fighting for themselves. And that’s what Kurdish forces vowed to do, as sporadic shelling continued into the evening.

Facebook Twitter Pinterest Civilians flee with their belongings. Photograph: Delil Souleiman/AFP via Getty Images

“We will clash against the Turks and not allow them to cross the border,” said Mustafa Bali, head of the Syrian Democratic Forces (SDF) media office. “We will use all our possibilities against Turkish aggression.”

A statement released by the general command of the SDF said: “The border areas of north-east Syria are on the edge of a possible humanitarian catastrophe. All indications and field information, including the military buildup on the Turkish side of the border indicate that our border areas will be attacked by Turkey in cooperation with the Syrian opposition tied to Turkey.

“This attack will spill the blood of thousands of innocent civilians because our border areas are overcrowded.”

The impact of the invasion on local communities is likely to send tens of thousands of people towards the Iraqi border, officials in Iraqi Kurdistan said. “We’re very worried about it,” one official said. “Of course we’d need to take care of them.”

Between Ras al-Ayn, and the town of Ain Issa – which was also bombed by Turkish jets – a local driver said the number of new exiles had started to grow by the evening, adding: “There are groups fleeing using whatever they find. People are scared of the artillery hitting hear the town.”

What will happen next is the subject of much speculation across the province, with the shifting global allegiances proving difficult to digest.

Facebook Twitter Pinterest Turkish soldiers with armoured vehicles during a military operation in Kurdish areas of northern Syria. Photograph: STR/EPA

The Russian foreign minister, Sergei Lavrov, tweeted to say he had asked the Kurds to start direct discussions with the Syrian government – a plan that is also seen locally as perhaps the only remaining buffer against the invading Turks.

The SDF said it welcomed Lavrov’s announcement. Privately, the Syrian Kurdish leadership has long harboured fears about the cost of a rapprochement with Damascus, which it has neither opposed nor supported during the eight-year civil war.

In Qamishli, the regional capital of the Kurdish province, which was hit by two shells in the afternoon barrage, the return of the Assad “regime” has been seen as inevitable in many quarters.

In fact, the Syrian military has not left the town during the war – continuing to man checkpoints in two neighbourhoods and the road to the city’s airport.

Several hours west, on the Iraqi side of the border, a Peshmerga guard pointed at nearby farmland, which he said had been attacked by the Turkish airforce during the night. “They were hitting the PKK, he said. “They might be difficult friends, but they’re still Kurds. We’re seeing a lot more people leaving the border than arriving. And we’re expecting many more.”