Surveillance aircraft that were monitoring an Islamic State in Iraq and Syria (ISIS) convoy stuck in the desert in eastern Syria have left the area at the request of Russian officials, the U.S.-led coalition said Friday.

“To ensure safe de-confliction of efforts to defeat ISIS, coalition surveillance aircraft departed the adjacent airspace at the request of Russian officials during their assault on Dawyr Az Zawyr,” the coalition said in a statement.

ISIS fighters and their family members have been stranded on eleven buses in the desert for more than a week.

ADVERTISEMENT

The convoy showdown began last month, when ISIS struck a deal with the Lebanese militant group Hezbollah — a chief ally of the Syrian government — for safe passage from an area near the Syrian border with Lebanon to ISIS-held territory in eastern Syria bordering Iraq. To get there, the original 17-bus convoy planned to travel through Syrian government-controlled territory.

The U.S.-led coalition, intent on making sure the convoy did not make it to the Iraqi border and link up with other ISIS fighters, cratered the road and destroyed a bridge with airstrikes. That forced six buses to turn back to Palmyra, a Syrian government-controlled city, and stranded the remaining 11.

A U.S. spokesman for the coalition told reporters Thursday that it has been striking ISIS fighters walking away from the convoy or trying to link up with the group, estimating that 85 ISIS fighters have been struck since the start of the standoff.

The coalition has not struck the convoy itself and has allowed food and water to get through, citing the women and children in the buses.

Col. Ryan Dillon, a spokesman for the coalition, also said Thursday that the United States had used the so-called deconfliction line it uses to communicate with the Russians to try to separate the women and children from the ISIS fighters. But Dillon said that effort had “not gained any traction."

Syrian forces broke a three-year ISIS siege on Deir al-Zour in eastern Syria earlier this week. As part of that assault, pro-Syrian regime forces advanced past the ISIS convoy Friday morning, according to the coalition.

“From the start of this situation on Aug. 29, we have placed responsibility for the buses and passengers on the Syrian regime, who in conjunction with Lebanese Hezbollah brokered a deal with ISIS to move its terrorists into Iraq,” Brig. Gen. Jon Braga, director of operations for the coalition, said in a statement. “The regime’s advance past the convoy underlines continued Syrian responsibility for the buses and terrorists. As always, we will do our utmost to ensure that the ISIS terrorists do not move toward the border of our Iraqi partners.”