Volunteers struggling to find ever fewer survivors in the quake-hit Turkish city of Antakya said on Saturday ransacking and hygiene problems were adding to their daunting task.

One resident, searching for a colleague buried in a collapsed building, said he witnessed looting in the first days after Monday's quake before leaving the city for a village.

"People were smashing the windows and fences of shops and cars," said Mehmet Bok, 26, now back in Antakya and searching for a work colleague in a collapsed building.

German aid organisations suspended rescue operations in the quake region on Saturday, citing security problems and reports of clashes between groups of people and gunfire.

Turkish authorities have not commented on any unrest, but President Tayyip Erdogan said on Saturday the government would deal firmly with looters and other criminal behaviour, noting that a state of emergency had been declared.

The death count has surpassed 25,300 in Turkey and Syria.

Another rescuer, Gizem from the southeastern province of Sanliurfa, said she had also seen looters in the four days she had been in Antakya.

"We cannot intervene much as most of the looters carry knives. They caught a looter today, people chased after him," she said in the city where there was a heavy police and military presence directing traffic, helping rescuers and handing out food.

She described Antakya as a place of death and destruction when she arrived. "We could not hold back our tears," she said as ambulance sirens wailed in the background.

"If people don't die here under the rubble, they'll die from injuries, if not they will die from infection. There is no toilet here. It is a big problem," she said, adding that there were not enough body bags for all the dead.

"The bodies are all over the roads, with only blankets on them."

Townsfolk were wearing masks to cover the smell of death.

Others echoed concerns about hygiene, especially insufficient numbers of working lavatories.

There were long lines at temporary mobile toilets but many people said they were simply finding a hidden spot, leading to complaints about stench.

"I think right now what's needed most is hygiene products. We have toilet problems, I am scared that some disease will spread," said one man, who declined to give his name and who travelled from Antalya to help in rescue operations.

He said there was little coordination, with everyone doing what they can to save lives and some collapsed buildings still untouched in side streets.

"We are digging for hours and hours," he said, describing pulling alive from the rubble overnight a 56-year old woman, her face covered with dust, who had fallen into the stairwell of an apartment building.

"We've pulled out some 150-200 dead bodies."