Turkey’s President Recep Erdogan has declared seven days of national mourning following devastating earthquakes that killed more than 5,000 people and toppled buildings across southeast Turkey and northern Syria, Aljazeera reported on Tuesday morning.

The media house noted that authorities fear the death toll from Monday’s predawn magnitude 7.8 temblor, followed by a magnitude 7.6 earthquake and several aftershocks will continue to climb as rescuers looked for survivors among tangles of metal and concrete spread across a region already suffering under Syria’s 12-year civil war and a refugee crisis.

Rescuers searched through the frigid night into Tuesday morning, hoping to dig more survivors out of the rubble as those trapped cried out for help from beneath mountains of debris.

Turkish Vice President Fuat Oktay said on Tuesday that the death toll from the earthquakes in Turkey had risen to 3,419.

Orhan Tatar, an official with Turkey’s Disaster and Emergency Management Authority said earlier on Tuesday that 20,426 others were injured. Tatar said more than 5,700 buildings had also been destroyed.

In Syria, at least 1,602 people were killed and about 3,500 others were injured, according to the Ministry of Health and the White Helmets rescue organization.

The US Geological Survey measured the initial earthquake at 7.8, with a depth of 18km (11 miles). Hours later, a 7.6 magnitude temblor also struck. 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.

More than 7,800 people have been rescued across 10 provinces, according to Orhan Tatar, an official with Turkey’s disaster management authority. Strained medical facilities have quickly filled with injured people, rescue workers said.