Rescuers are racing to rescue survivors from the rubble of thousands of buildings brought down by a magnitude 7.8 earthquake and multiple aftershocks that struck eastern Turkey and neighbouring Syria, killing at least 7,300 people, with the number expected to sharply rise.

Countries from around the globe have dispatched teams to assist in the rescue efforts, but on Tuesday, a day after the earthquake struck, the number of emergency crews on the ground remained few, with their efforts impeded by frigid temperatures and close to 200 aftershocks, making the search through unstable structures perilous.

Across Hatay province, just southwest of the earthquake’s epicentre, officials say that as many as 1,500 buildings were destroyed and many people reported relatives being trapped under the rubble with no aid or rescue teams arriving.

In the Turkish city of Gaziantep, a provincial capital about 33 kilometres (20 miles) from the epicentre, people took refuge in shopping malls, stadiums, mosques and community centres.

In the latest pledges of international help, South Korean President Yoon Suk-yeol said he was preparing to swiftly dispatch a 60-person search and rescue team as well as medical supplies.

Pakistan’s government sent a flight carrying relief supplies and a 50-member search and rescue team early on Tuesday, and said there would be daily aid flights to Syria and Turkey from Wednesday. India said it would send two search and rescue teams, including specially trained dogs and medical personnel.

The quake piled more misery on a region that has seen tremendous suffering over the past decade.

On the Syrian side, the affected area is divided between government-controlled territory and the country’s last opposition-held enclave, which is surrounded by Russian-backed government forces. Turkey is home to millions of refugees from the Syrian civil war.

In the rebel-held enclave, hundreds of families remained trapped in the rubble, the opposition emergency organisation known as the White Helmets said in a statement.

The area is packed with some four million people displaced from other parts of the country by the war. Many live in buildings that were already damaged by military bombardments.

The United States Geological Survey measured Monday’s quake at 7.8, with a depth of 18 kilometres (11 miles). Hours later, another quake, likely triggered by the first, struck more than 100 kilometres (60 miles) away with a 7.6 magnitude.

The second jolt caused a multi-storey apartment building in the Turkish city of Sanliurfa to topple onto the street in a cloud of dust as bystanders screamed, according to video of the scene.

Thousands of buildings were reported collapsed in a wide area extending from Syria’s cities of Aleppo and Hama to Turkey’s Diyarbakir, more than 330 kilometres (200 miles) to the northeast.

The region sits on top of major fault lines and is frequently shaken by earthquakes. Some 18,000 people were killed in similarly powerful earthquakes that hit northwest Turkey in 1999.