Despite vaccinating his entire herd against foot-and-mouth disease, Iraqi farmer Saadoun Roumi has lost five of his 15 buffaloes to a variant never before seen in the country.

The severe, highly contagious livestock disease has plagued Iraq for decades, but this year's outbreak has already had a devastating impact described as unprecedented by veterinarians in Nineveh province.

Laboratory tests have identified the SAT2 variant of the viral disease, the United Nations' Food and Agriculture Organization (FAO) said.

The stakes could hardly be higher for Turkish President Recep Tayyip Erdogan.

Just three months before the biggest test of his political career, a massive 7.8-magnitude earthquake rocked Turkey and Syria, killing more than 15,000 people.

On May 14, Turkey will vote in presidential and parliamentary elections that polls conducted before the disaster showed would turn into a tight race for Erdogan, who has led the country since 2003.

And even before disaster struck in the pre-dawn hours of Monday, Erdogan was trying to put out a series of crises at the same time.

Temperatures in the quake-stricken Turkish city of Gaziantep plunged to minus five degrees Celsius early Thursday but thousands of families spent the night in cars and makeshift tents -- too scared or banned from returning to their homes.

Parents walked the streets of the city -- close to the epicentre of Monday's earthquake that has left more than 12,000 dead -- carrying their children in blankets because it was warmer than sitting in a tent.

Malek Ibrahim made it out of his home after the earthquake hit Syria and thought he could breathe a sigh of relief. But 30 relatives were still unaccounted for elsewhere.

For the past two days, Ibrahim has been doggedly tearing at the rubble with his hands as he searches for family members who were buried when Monday's deadly earthquake struck both Syria and Turkey.

So far, he has managed to retrieve 10 bodies, helped by residents and rescuers in Besnaya, a village in the northwest on the Turkish border that was hard-hit by the disaster.

A leading United Nations official on Wednesday called for the facilitation of aid access to rebel-held areas in Syria's northwest, warning that relief stocks will soon be depleted.

Rebel-held areas near Turkey's border -- hard hit by the 7.8 magnitude earthquake that struck on Monday -- cannot receive aid from government-held parts of Syria without Damascus's authorisation.

Green metal coffins were lined up 10 at a time under a shelter at Gaziantep's main cemetery on Wednesday for an imam to bless victims of Turkey's devastating earthquake before their hurried burial.

While rescuers searched rubble for survivors and aftershocks rattled Gaziantep, Yesilkent Cemetery overflowed with grieving relatives who had come from across the region.

The magnitude 7.8 quake and subsequent aftershocks killed more than 11,200 people and Gaziantep was near the epicentre.

Ridwan Gurre had the instincts to hide from roaring warplanes when he lived in Syria during its civil war.

But little prepared him for the rumble of the 7.8-magnitude quake that devastated his adopted home in Turkey on Monday.

The 42-year old joined nearly four million Syrians when he moved his family for the relative safety of southeastern Turkey -- a region that has suffered its own share of violence between militants and government forces.

He spent seven years building a new home in the multi-ethnic city of Diyarbakir. His life was getting back on track.

Freezing temperatures deepened the misery Thursday for survivors of a massive earthquake in Turkey and Syria that killed more than 16,000 people, as rescuers raced to save countless people still trapped under rubble.

The death toll from Monday's 7.8-magnitude quake is expected to rise sharply as rescue efforts pass the 72-hour mark that disaster experts consider the most likely period to save lives.

Turkish President Recep Tayyip Erdogan on Wednesday conceded "shortcomings" after criticism of his government's response to the earthquake, one of the deadliest this century.

The White Helmets leading efforts to rescue people buried under rubble in rebel-held areas of earthquake-hit Syria appealed Wednesday for international help in their "race against time".

First responders from the group that was formed a decade ago to save the lives of civilians during Syria's civil war sprung into action early Monday when a 7.8-magnitude quake rocked Turkey and Syria.

They have been toiling ever since to pull survivors out from under the debris of dozens of flattened buildings in northwestern areas of Syria outside government control.

With every passing moment, Ebru Firat knows the chances dim of finding her cousin alive under the rubble of a flattened building in the southern Turkish city of Gaziantep.

And with that fading hope, the 23-year-old's grief is being replaced by rage at the government's earthquake response.

Monday's 7.8-magnitude pre-dawn tremor killed more than 7,800 people across swathes of Turkey and Syria, injured tens of thousands and left many more without shelter in the winter cold.

"I have no more tears left to cry," she said.