More than 46,000 people have been killed in the earthquake that struck Turkey and Syria and the toll is expected to soar, with some 345,000 apartments in Turkey now known to have been destroyed, and many still missing.

As Turkey attempts to manage its worst modern disaster, concerns were growing over the victims of the tragedy in Syria, with the World Food Programme (WFP) pressuring authorities in the northwest to stop blocking access to the area as it seeks to help hundreds of thousands of people ravaged by earthquakes.

Twelve days after the quake hit, workers from Kyrgyzstan tried to save a Syrian family of five from the rubble of a building in Antakya city in southern Turkey.

Three people, including a child, were rescued alive. The mother and father survived but the child died later of dehydration, the rescue team said. One older sister and a twin did not make it.

"We heard shouts when we were digging today an hour ago. When we find people who are alive we are always happy," Atay Osmanov, a member of the rescue team, told Reuters.

Ten ambulances waited on a nearby street that was blocked to traffic to allow the rescue work.

Workers asked for complete silence and for everybody to crouch or sit as the teams climbed further up to the top of the rubble of the building where the family was found to listen for any more sounds using an electronic detector.

As rescue efforts continued one worker yelled into the rubble: "Take a deep breath if you can hear my voice."

The head of Turkey's Disaster and Emergency Management Authority (AFAD), Yunus Sezer, said the search and rescue efforts will largely be terminated on Sunday night.

The death toll in Turkey stands at 40,642 from the quake while neighbouring Syria has reported more than 5,800 deaths, a toll that has not changed for days.

Speaking to Reuters on the sidelines of the Munich Security Conference, WFP Director David Beasley said the Syrian and Turkish governments had been cooperating very well, but that its operations were being hampered in northwestern Syria.

The agency last week said it was running out of stocks there and called for more border crossings to be opened from Turkey.

"The problems we are running into [are with] the cross-line operations into northwest Syria where the northwestern Syrian authorities are not giving us the access we need," said Beasley.

"That is bottlenecking our operations. That has to get fixed straight away."

"Time is running out and we are running out of money. Our operation is about $50 million a month for our earthquake response alone so unless Europe wants a new wave of refugees, we need get the support we need," Beasley added.

In Syria, already shattered by more than a decade of civil war, the bulk of fatalities have been in the northwest.

The area is controlled by insurgents at war with forces loyal to President Bashar al-Assad which has complicated efforts to get aid to people.

Thousands of Syrians who had sought refuge in Turkey from the civil war have returned to their homes in the war zone - at least for now.

Public health

Medics and experts voiced concerns over the possible spread of infection in the area where tens of thousands of buildings collapsed last week leaving sanitation infrastructure damaged.

Turkish Health Minister Fahrettin Koca said on Saturday that although there had been a rise in intestinal and upper respiratory infections, the numbers did not pose a serious threat to public health.

"Our priority now is to fight against the conditions that can threaten public health and to prevent infectious diseases," Koca told a news conference in southern Hatay province.

Aid organisations say the survivors will need help for months to come with so much crucial infrastructure destroyed.

Anger grows

Neither Turkey nor Syria have said how many people are still missing following the quake.

For families still waiting to retrieve relatives in Turkey, there is growing anger over what they see as corrupt building practices and deeply flawed urban development that resulted in thousands of homes and businesses disintegrating.

One such building was the Ronesans Rezidans (Renaissance Residence), which keeled over in Antakya, killing hundreds.

"It was said to be earthquake-safe, but you can see the result," said Hamza Alpaslan, 47, whose brother had lived in the block. "It's in horrible condition. There is neither cement nor proper iron in it. It's a real hell."

Turkey has promised to investigate anyone suspected of responsibility for the collapse of buildings and has ordered the detention of more than 100 suspects, including developers.