At least 968 people were killed in Syria on Monday as buildings collapsed after a 7.8 magnitude earthquake struck neighbouring Turkey, state media and rescuers said.
The quake killed at least 538 people and left at least another 1,353 injured in government-controlled parts of Syria, including the provinces of Aleppo, Hama, Latakia and Tartus, the health ministry said.
In rebel-held parts of the northwest of the country, at least 430 people were killed and more than 1,050 were injured, the White Helmets rescue group said, warning the toll could increase.
"Rescue efforts in northwest Syria are facing immense difficulties" because heavy equipment is required, said the group, which operates in rebel-controlled areas of the war-torn country.
It said more than 160 buildings had completely collapsed, while 330 had been partially levelled, and thousands of others had been damaged.
AFP correspondents in northern Syria said terrified residents ran out of their homes after the earthquake hit before dawn near the Turkish city of Gaziantep, about 40 kilometres (25 miles) from the Syrian border.
Rescuers rushed to search for survivors beneath the rubble of collapsed buildings, under the pouring winter rain.
- Government appeal -
The Syrian government urged the international community to come to its aid.
More than a decade of conflict -- which began with the regime's brutal repression of mostly peaceful protests -- and years of economic sanctions have devastated the country's economy and its ability to respond to large-scale disasters.
"Syria appeals to member states of the United Nations... the International Committee of the Red Cross and other humanitarian" groups to support "efforts to face the devastating earthquake", the foreign ministry said in a statement.
Foreign Minister Faisal Mekdad said his government was ready "to provide all the required facilities to international organisations so they can give Syrians humanitarian aid", after meeting with UN representatives and aid groups.
In northern Aleppo alone, 156 people died and 507 were injured when 46 buildings collapsed in the province, the official news agency SANA had said, quoting an official.
Even before the quake, buildings in Aleppo -- Syria's pre-war commercial hub -- often collapsed due to poor infrastructure.
Many buildings there are dilapidated after more than a decade of war and little oversight to ensure the safety of new construction projects, some of which have gone up illegally.
Several of Syria's archaeological sites including Aleppo's famed citadel were also damaged in the quake, the country's antiquities authority said.
- Schools closed -
The earthquake was felt from Latakia on the coast in the west all the way to the capital Damascus hundreds of kilometres (miles) further south, SANA said.
"This earthquake is the strongest since the National Earthquake Centre was founded in 1995," Raed Ahmed, who heads the centre, told SANA.
He said 25 aftershocks had struck the country following the morning quake.
In the city of Hama, an eight-storey building collapsed, with rescuers and civil defence forces still searching for survivors under the rubble, SANA said.
Alaa Shaker of the Syrian Red Crescent told AFP that around 125 people lived in the building.
Schools will be closed across Syria until the end of the week, the education ministry said.
The transport ministry said the Banyas oil refinery had stopped working after it was damaged in the quake.
Near the border town of Azaz, an AFP correspondent saw rescuers pull survivors as well as five bodies from the rubble of a three-storey building that had collapsed.
Dozens of rescuers and residents had toiled in the darkness, using flashlights to look for survivors in the debris.
The earthquake hit near Gaziantep in southeastern Turkey at 04:17 am (0117 GMT) at a depth of about 17.9 kilometres (11 miles), the US Geological Survey said.
Tremors were also felt in Lebanon and Cyprus, AFP correspondents said.