More than 500 people have been killed and over 3,000 others injured in Turkey and Syria after a powerful magnitude 7.8 earthquake hit southern Turkey early Monday.

The quake, one of the strongest to hit the region in more than 100 years, struck 23 kilometers (14.2 miles) east of Nurdagi, Gaziantep province, at a depth of 24.1 kilometers (14.9 miles), the US Geological Survey said.

Multiple strong aftershocks have been felt across the region, including as far away as Lebanon and Israel.

Turkey’s disaster agency appealed for help from the international community as it conducts search and rescue operations.