Authorities in Turkey and Syria on Tuesday staged a massive effort to find survivors and help victims after a devastating earthquake left almost 5,000 people dead, but fraught road and weather conditions threatened to snarl rescuers’ attempts to stem a worsening crisis.

Authorities were pulling people out of the rubble in freezing temperatures in south-eastern Turkey and north-western Syria, where there was sporadic snowfall.

More than 10,000 people and thousands of pieces of heavy machinery were engaged in the rescue effort, with aid organisations rushing to provide basic necessities and calling for blood donors as the humanitarian toll mounted. Turkish television showed collapsed buildings, mangled metal and roads that buckled across numerous towns and cities.

The effort came after the worst earthquake in eight decades struck near the city of Gaziantep, Turkey, early on Monday, toppling thousands of buildings over a vast area. More than 300 aftershocks continued to rumble through the region following the initial quake, according to Fuat Oktay, Turkey’s vice-president.

The death toll in Turkey reached 3,419 people, with 20,426 injured, according to the country’s disaster relief agency Afad. At least 769 people were killed in government-held areas in Syria, with more than 1,448 injured, according to the country’s health ministry. In the rebel-held north-west, more than 790 people died and in excess of 2,200 were injured, according the Syria Civil Defence, the aid workers also known as the White Helmets. The total confirmed death toll across the two countries stands at 4,940.

Local television stations had wall to wall coverage of one of the worst natural disasters in modern Turkish history. Witnesses in the southern city of Hatay described hearing cries for help from people stuck under the rubble that went unanswered as rescuers struggled to reach the city, while images showed a blaze shooting up from its Mediterranean port.

Turkish authorities closed roads to Hatay, Kahramanmaraş and Adıyaman — all hard-hit cities — for two days to anyone besides rescue and aid vehicles, as they attempt to overcome the logistical challenges posed by the disaster. Some people on the ground complained that rescuers were either too slow or had failed to appear, while they battled with a lack of clean water and electricity.

In a sign of the potential economic fallout, Turkey’s benchmark Bist 100 stock index tumbled 7 per cent, triggering curbs designed to smooth panicky trading.

The Turkish lira also hit a new record low on Tuesday, according to Bloomberg data, after a long slide caused in large part by the government’s unorthodox policy of lowering interest rates despite scorching inflation.

Experts said the low quality of buildings in the affected region and lack of resilience to earthquakes contributed to the huge destruction. Many buildings were “not designed from seismic considerations to absorb this much ground motion”, said Kishor Jaiswal, a scientist at the US Geological Survey.

“It’s difficult to watch this tragedy unfold, especially since we’ve known for a long time about how poorly the buildings in the region tend to behave in earthquakes,” he added.

Turkey’s Red Crescent aid group said it was shipping emergency supplies “nonstop”, with almost 2,000 tents and 27,000 blankets in addition to mobile kitchens and catering facilities reaching the affected area.

Teams of Turkish rescue workers have been filtering through Istanbul’s main airport since Monday, many sleeping on the floor and resting their heads on helmets and sleeping bags while waiting for flights.

Different Turkish aid groups were heading to cities including Adana, to join efforts to clear the rubble and rescue those trapped under it.

“We have to do everything we can to help,” said Sinan Aksoy, 34, a firefighter who was on his way to the southern city with a group of about 50 volunteers. “We’re running against time to find people alive.” 

Turkey’s central bank ordered local lenders not to charge transaction fees on fund transfers to accounts collecting earthquake relief donations and eased conditions on certain types of credit extended to companies in the stricken region.