The Islamic State group Friday took control of the Syrian town of Azaz on the Turkish border, trapping 50,000 civilians in a small stretch of land, many of them in the makeshift Bab al-Salama camp. The takeover shut down the border crossing completely, preventing humanitarian organizations from delivering aid to people trapped inside the besieged country.

Over the past five years the town of Azaz has switched hands multiple times. In the beginning stages of the war, the Syrian army occupied the town and the road that led out of the country. Then it was liberated by soldiers affiliated with the Free Syrian Army, the main opposition group at the time. Since then, various rebel groups have fought one another over control over the city because of its location on the border with Turkey and its proximity to the major city of Aleppo.

Humanitarian organizations such as the United Nations, Doctors Without Borders and the World Food Program have always relied on the Azaz crossing to deliver aid inside Syria. Although it also uses another crossing, called Bab al-Hawa, the crossing near Azaz, called Bab al-Salama, provides organizations with a more direct route to civilians trapped by the fighting in the northern Aleppo countryside.

Although the Bab al-Salama border crossing has closed several times, this is the first time in several years that Doctors Without Borders is not evacuating just its staff from the makeshift border camp but also its patients.

“We are terribly concerned about the fate of our hospital and our patients, and about the estimated 100,000 people trapped between the Turkish border and active front lines,” Pablo Marco, Doctors Without Borders' operations manager for the Middle East, said in a statement. “For some months, the front line has been around seven kilometers away from the hospital. Now it is only three kilometers from al-Salama town. There is nowhere for people to flee to as the fighting gets closer.”

Humanitarian funding for Syria civilians falls under what is known as the Syria Response Plan. The plan includes the participation of dozens of humanitarian organizations and is overseen by the United Nations. As of December, the 2015 plan had received only $1.17 billion, or about 41 percent, of its overall funding requirements. In February, though, the U.N.'s World Food Program received a donation of $675 million, allowing it to reinstate its food services to people living inside Syria until at least October 2016. WFP had previously been unable to send aid convoys into the country because it lacked the necessary funding. Today there are still more than 2 million people in need of access to the U.N.'s food security program.

The U.N. Office for the Coordination of Humanitarian Affairs said in February it would deliver food and medical supplies to about 154,000 people living in besieged locations inside Syria. Now that ISIS has taken Azaz, though, the organization will need to divert its convoys through the Bab al-Hawa border crossing, which is also hotly contested.
The Syrian army, with Russian air support, has stepped up its campaign to besiege Aleppo despite the continuing peace talks. A cessation of hostilities, a type of ceasefire, exists in northern Syria, but civilians continue to die under President Bashar Assad's bombs.

This month the army turned back aid convoys trying to enter a Damascus suburb. The convoys were refused entry to Daraya despite having obtained prior clearance from all sides.