WASHINGTON — Rescue workers from around the world are streaming into Turkey but aid is arriving at a much slower pace in Syria, where more than a decade of conflict has created major hurdles for aid workers trying to reach survivors of Monday's powerful earthquake. 

Among the areas worst hit was the northwest Syrian province of Idlib, much of which had already been reduced to rubble during years of government airstrikes that destroyed basic infrastructure, wreaked havoc on the local economy and sent a flood of displaced people to tented camps on Turkey’s doorstep.

The 7.8 magnitude earthquake that struck early Monday, which was followed hours later by a second powerful shock along the same fault line, has compounded what was an already dire humanitarian situation in Syria’s opposition-controlled northwest. 

The pro-opposition Syrian Observatory for Human Rights said Tuesday at least 1,621 people in Syria have died as a result of the earthquake, which also left thousands dead in Turkey. The death toll in both countries, however, is expected to rise significantly as emergency responders pull more bodies from the rubble.