Isil jihadists in Syria have advanced on towns and villages close to the Turkish border, laying siege to one of the last supply routes into the city of Aleppo.
In a lightening strike, the jihadists have captured up to 25 villages in Aleppo province and closed in on the border town of Azaz, one of the last hubs for aid agencies providing help to tens of thousands of civilians trapped in war-riven Aleppo.
"It's a horror of death and bombing," said one aid worker in the area, who asked to remain anonymous for fear of attacks from Islamic State of Iraq and the Levant (Isil).
"Today Azaz is being shelled. Humanitarian agencies were providing food and hygiene kits to people in Aleppo. But two nights ago, when the campaign began, they had to take what they could from the warehouses and escape."
Azaz and villages around were bases for the major NGOs still working in Aleppo, a city devastated by years of war, local residents said.
Until the weekend aid workers had been able to continue operating in the area, sending aid from the warehouses down a central highway into rebel-held parts of northern Aleppo.
But as night fell the jihadists descended upon Azaz, taking surrounding villages as they advanced.
The Violation Documentation Centre, a monitoring group, confirmed that the jihadists had taken as many as 25 villages or hamlets in north-west Aleppo in the past week.
"Isil are attacking with all kinds of weapons. They shelled the city with tanks even," the resident said.
Azaz, flooded with thousands of refugees fleeing violence across northern Syria, has also been a major arms route and commercial thoroughfare for hundreds of trucks carrying Turkish goods to rebel-held areas in Aleppo and Idlib provinces.
As civilians and aid workers streamed out of the area, rumours grew of gory atrocities committed by the jihadists against their enemies.
There were unconfirmed reports that in Soran, a town near Azaz, Isil had rounded up fighters from other rebel groups and executed them. They had then taken the fighters' wives and female relatives as "slaves".
"This is something normal now," a resident said. "Isil is a group that focuses on resources. When they attack their enemy they take everything: their money, their land, and their women".
The strike came as Geish al-Fateh, a broad coalition of rebel groups, had been preparing to mount an offensive on the Syrian regime, which still controls parts of southern Aleppo.
The coalition has won a string of victories against the government in recent months, mostly clearing Idlib province of any regime presence. Aleppo was the logical next step.
But instead, the rebels have redirected their focus on Azaz and the north, fighting against Isil instead of the regime.
The jihadists have also focused on attacking Marea, a town north of Aleppo which has long been a hub for other rebel groups.
Rebels in the area have been fighting to stop the jihadist groups from taking the town, but their defences have been weakened by a series of airstrikes launched against rebel positions by the regime, local activists reported.
Separately yesterday, at least four people were killed when dozens of tents at a Syrian refugee camp in Lebanon's Bekaa Valley caught fire, witnesses said.
Security sources initially said six people were killed. The witnesses who were in the camp said that four people including three children were killed and two remained missing.
At least 160 of the roughly 300 tents, which housed around 600 people, were burned, humanitarian sources said, adding that the cause of the fire was not immediately known. Some said that the fire was caused by an electrical fault; others said a tent caught fire when a woman was cooking and it spread quickly.
"The bodies were totally burned and cannot be recognised. Some are children," a security source said.
Syrian civil war refugees in Lebanon live in dire conditions - makeshift settlements, sheds, garages and unfinished buildings. Some of the tents are made of old billboard posters
The four-year conflict has displaced millions of Syrians.
Around 1.7 million are refugees in neighbouring countries such as Jordan, Turkey and Lebanon.
In Lebanon, where a quarter of the population are now refugees, the authorities have barred the United Nations from opening formal camps, which has meant that displaced people are scattered across some 1,700 communities. (© Daily Telegraph, London)