Hundreds of structures were destroyed and over 1,300 people were killed when a powerful 7.8 magnitude earthquake hit large sections of Turkey and Syria early on Monday. As rescuers continued to comb through piles of debris in cities and towns across the region, they feared the death toll might increase to hundreds.

Residents on both sides of the border were awakened by the tremor and ran outdoors into the cold, wet, and wintry night. Major aftershocks, some nearly as powerful as the first, persisted as buildings collapsed into heaps of pancaked floors.

Residents and rescue personnel from different locations combed amid twisted metal and concrete in search of survivors. After the collapse of a hospital in Turkey, patients in Syria had to be transferred to other hospitals, including infants.

In the Turkish city of Adana, one resident said three buildings near his home were toppled. “I don’t have the strength anymore,” one survivor could be heard calling out from beneath the rubble as rescue workers tried to reach him, said the resident, journalism student Muhammet Fatih Yavus.

“Because the debris removal efforts are continuing in many buildings in the earthquake zone, we do not know how high the number of dead and injured will rise,” Turkish President Recep Tayyip Erdogan said. “Hopefully, we will leave these disastrous days behind us in unity and solidarity as a country and a nation.”

The earthquake, located north of the provincial seat of Gaziantep, Turkey, was felt as far away as Cairo. It caused citizens of Damascus to run onto the street and jolted awake those sleeping in Beirut.

It struck a territory that has been impacted by the Syrian civil conflict on both sides of the border for more than a decade. On the Syrian side, the impacted area is divided between government-held territory and the final opposition-held enclave, which is encircled by government forces supported by Russia. Meanwhile, millions of refugees from this violence reside in Turkey.

The violence in Syria has displaced around four million people from other areas of the nation to the opposition-held districts. Many of them reside in structures that have been damaged by previous bombings. White Helmets, an opposition emergency organization, stated in a statement that hundreds of families were still buried beneath the wreckage.

According to rescue personnel, overcrowded medical institutions and hospitals were rapidly flooded with injured patients. Others, including a maternity facility, had to be evacuated, according to the SAMS medical association.

The area is regularly rocked by earthquakes due to its location on major fault lines. In 1999, a comparably large earthquake struck northwest Turkey, killing over 18,000. The United States Geological Survey assessed the magnitude of Monday’s earthquake as 7.8. At least 20 aftershocks followed, with one measuring 7.5 magnitudes, according to officials.

Thousands of buildings were reported to have fallen in a large region stretching from Aleppo and Hama in Syria to Diyarbakir, Turkey, more than 330 kilometers (200 miles) to the northeast. His vice president, Fuat Oktay, stated that the number of casualties was unknown at this time following the collapse of a hospital in Iskenderun, a city on the Mediterranean coast.

Television stations in Turkey broadcast live news of rescue attempts in the worst-affected areas on four or five screens. Two children were rescued from the wreckage in the city of Kahramanmaras, while others attempted to reach a relative.

Dozens of nations, as well as the European Union and NATO, offered assistance in the form of search-and-rescue teams, medical supplies, and financial aid.

Dr. Steven Godby, an expert on natural disasters at Nottingham Trent University, said that the damage evident in photos of the affected areas is typically associated with a significant loss of life, while bitterly cold temperatures and the difficulty of working in areas beset by civil war will only complicate rescue efforts.

In Turkey, individuals attempting to flee quake-ravaged regions caused traffic jams, impeding the operations of rescue organizations attempting to reach the afflicted areas. Officials encouraged citizens to stay off the roadways. Throughout the region, mosques were opened to give shelter for those unable to return to their damaged houses due to cold conditions.

According to the president of Turkey, more than 900 people were murdered and more than 5,400 were injured in ten Turkish regions. According to the Ministry of Health, the death toll in Syria’s government-held territories has risen to over 330, with around 1,000 wounded. More than 200 individuals were killed in rebel-held regions, according to the White Helmets, while the SAMS medical organization placed the death toll at more than 135. Both organizations said that hundreds were injured.