Tens of thousands of civilians have fled Syria's Idlib province to the Turkish border, after an increase in bombings by Russia-backed government forces, creating a new humanitarian challenge as the winter season arrives.

United Nations observers said on Friday that at least 18,000 people have been displaced in Idlib in just 24 hours, as the deadly bombardments continue.

On Friday morning, at least seven more people were reported killed, after at least 19 civilians were killed on Thursday.

In the last five days, at least 80,000 Syrians have already fled near Turkey's border, according to reports quoting Syria's Response Coordination Group.

There are already about one million Syrian refugees living near the border with Turkey.

In September 2018, Turkey and Russia had agreed to turn Idlib into a de-escalation zone.

Since then, more than 1,300 civilians have been killed in attacks by the Syrian government forces in the de-escalation zone, according to reports.

Al Jazeera's Mohammed Adow, reporting from Istanbul, said the Russian-backed Syrian government bombings include air raids, shelling and barrel bomb attacks in the town of Maarat el-Numan in southern Idlib.

Syrians living in the area said the attacks were indiscriminate with hospitals, markets and homes targeted.

On Friday, public anger against the offensive spilled onto the streets, with hundreds of people in Idlib taking to the streets to denounce what they called the neglect of their plight by the International community. They also called for a swift halt to the bombardment.

Witnesses also said that evacuees were targeted as they tried to flee their homes.

In the town of Sarmada, a hub for aid going into Syria and just a few kilometres from the border with Turkey, fighters from the opposition Hay'et Tahrir Sham set up barriers to stop protesters from walking towards the border.

Turkish security forces said they were forced to send reinforcements to ensure protesters did not cross into Turkey.

Cold, hungry winter

Idlib is home to an estimated 2.4 million people, more than half of whom are internally displaced and living camped out near the Turkish border.

With the intensified bombing campaign forcing thousands to flee, many face a cold and hungry winter.

Official camps on the Syria-Turkey border are already in full capacity, forcing many of the newly-displaced civilians to live in flooded makeshift camps, where aid deliveries are few and far between.

Crippling fuel shortages, which have raised the cost of food and transport, also threaten medical care in the province.

Fuel prices have more than doubled in the past two months, and charities and hospitals said they are struggling to respond to the crisis.

As the situation on the ground deteriorates, the UN Security Council failed to approve any of the rival resolutions that would continue the delivery of humanitarian aid across borders to more than a million Syrians every month in mainly rebel-held areas.

A resolution, cosponsored by Germany, Belgium and Kuwait and supported by the UN humanitarian office, which would have extended the mandate for deliveries for six months and cut one of four crossing points, was vetoed by Russia, the Syrian government's closest ally, and China.

A rival resolution sponsored by Russia and China, introduced only on Monday, was also defeated.

The current year-long mandate for aid deliveries through four border crossings in Turkey, Iraq and Jordan is set to expire on January 10.

Secretary-General Antonio Guterres said in a report to the council circulated on Monday that "the United Nations does not have an alternative means of reaching people in need in the areas in which cross-border assistance is being provided."

UN spokesman Stephane Dujarric called the humanitarian situation in northwest and northeast Syria "horrific", saying "it would be markedly worse without the cross-border operation".

Al Jazeera