The toll, which currently stands at more than 4,500 people, has increased rapidly as the region faced the first earthquake on Monday morning followed by a second powerful tremor about 12 hours later.
The warning from the world health body comes as rescuers have been combing through the rubble in freezing weather to find survivors. Countries around the world have stepped up to send support in order to aid the rescue efforts.
Turkey and Syria were struck by 7.8 magnitude tremor at 04:17 local time (01:17 GMT) at a depth of 17.9km (11 miles) near the city of Gaziantep, US Geological Survey (USGS) said, marking the largest ever quake recorded in Turkey which shook the country for about two minutes.
The second quake had a magnitude of 7.5, and its epicentre was in the Elbistan district of Kahramanmaras province, USGS said, adding that many aftershocks are still being felt across the region.
The WHO warned that the death toll is likely to increase as much as eight times, saying, “We always see the same thing with earthquakes, unfortunately, which is that the initial reports of the numbers of people who have died or who have been injured will increase quite significantly in the week that follows.”
The agency also said that the cold weather could leave many people without shelter, adding to the dangers, AFP reported.
Across both the countries thousands of buildings, several videos shared widely on social media showed. Roads have been destroyed and there are huge mountains of rubble as far as the eye can see in images coming out of the two countries.
