ANKARA, Turkey — A 7.8-magnitude quake toppled several buildings in southeastern Turkey and Syria early Monday, with many feared casualties.

Initially at least 10 deaths were reported in Turkey.

In northwestern Syria, the opposition Syrian Civil Defense described the situation in the rebel-held region as «disastrous», adding that entire buildings had collapsed and people were trapped under rubble. The civil defense urged people to evacuate buildings to gather in open areas.

The US Geological Survey said the quake was centered about 20 miles from Gaziantep, a major city and provincial capital. It was centered 11 miles down and a strong 6.7 aftershock rumbled about 10 minutes later.

Turkey’s Disaster and Emergency Management agency, AFAD, said the quake measured 7.4 and was centered in the city of Pazarcik in Kahramanmaras province.

In Sanliurfa, at least 10 deaths have been confirmed, according to Governor Salih Ayhan.

The tremor was centered in the country’s Pazarcik district, in Kahramanmaras province, according to the state-run Anadolu agency, citing emergency management officials.

The outlet published a photo of a pancaked building, window shades exposed to the air, furniture crushed and water fixtures detached from the pipes. His location was not made clear.

President Recep Tayyip Erdoğan said the country’s Emergency and Disaster Management Authority was ready to respond to requests for rescue and other forms of aid, according to Anadolu.

The tremor near Syria’s northern border was followed by a 6.7 quake about 11 minutes later, according to the survey. The region is seismically active, he said, and the initial quake appears to be near a tectonic triple junction, between the Anatolian, Arabian and African plates, the USGS said.

The 7.8 quake originated 11 miles deep, according to the US Geological Survey. Turkish officials initially measured it at magnitude 7.4.

It was also felt in Lebanon and Syria.

The country continued to shake as aftershocks rumbled throughout the day. The USGS recorded subsequent tremors of magnitude 5.6, 5.1, and 5.2, in that order.

Syrian state media reported that some buildings collapsed in the northern city of Aleppo and the central city of Hama.

In rebel-held northwestern Syria bordering Turkey, several buildings have collapsed, according to the opposition Syrian Civil Defense.

The quake knocked Lebanon’s residents out of their beds and shook buildings for about 40 seconds. Many Beirut residents left their homes and took to the streets or drove away from buildings in their cars.

Turkey sits on large fault lines and is frequently shaken by earthquakes; 18,000 people died in the powerful earthquakes that struck northwestern Turkey in 1999.

The recorded history of earthquakes in the region stretches back hundreds of years, according to the USGS, which said Monday’s temblor occurred on the East Anatolian fault zone or Dead Sea transform fault zone.

The last major shaking in the region took place on January 24, 2020, and measured 6.7, the USGS said. It was northeast of Monday’s quake, he said.

Nearby Aleppo, Syria, was hit by what experts estimate was a magnitude 7.1 earthquake in 1138, according to the survey. An earthquake with an estimated magnitude of 7.0 struck the same area of ​​Syria in 1822, he said.