More than 21,000 people have died in Syria and Turkey and thousands are injured after a massive quake on Monday. Round-the-clock rescue operations are on but snow and rain are adding to the difficulties of the survivors.

Here are 10 facts about the big story:

1. The death count in the Turkey-Syria earthquake has crossed 21,000. Officials say 17,674 people have died in Turkey and 3,377 in Syria, bringing the confirmed total to 21,051.

2. Rescue efforts, on the fourth day, are being conducted round-the-clock to save those still trapped under the rubble.

3. Some of the heaviest devastation occurred near the earthquake's epicentre in Gaziantep, where entire city blocks lay in ruins.

4. Eyewitness in Turkey's Gaziantep tell NDTV that multi-storeyed buildings turned to dust in less than two seconds.

5. The government said that nearly 3,000 buildings, including public hospitals, collapsed in seven cities.

6. Cold, hunger and despair gripped hundreds of thousands of people left homeless.

7. The rescue of a 2-year-old boy after 79 hours trapped in the rubble of a collapsed building in Hatay and several other people raised spirits among weary search crews. But hopes were fading that many more would be found alive in the ruins of towns and cities.

8. India has initiated "Operation Dost" to help Turkey and Syria in the aftermath of the quakes. Under the operation, India has sent rescue teams, medical teams and other supplies to the two disaster-hit nations.

9. The Indian Army has also set up a field hospital in Hatay which will is equipped with surgical and emergency wards.

10. The United States today announced an initial $85 million package for emergency relief for Turkey and Syria. America said the funding will go to partners on the ground "to deliver urgently needed aid for millions of people" including through food, shelter and emergency health services.