A convoy of Islamic State fighters began moving back toward the interior of Syria on Thursday after U.S.-led airstrikes hindered the militants from reaching the country’s eastern border with Iraq, according to the commander for the anti-ISIS coalition.

The retreat signals failure for a ceasefire deal involving the Bashar al-Assad regime, the Lebanese government, and Hezbollah struck earlier this week granting ISIS safe evacuation from Syria’s western border with Lebanon to a militant-held enclave on the Iraqi border.

The U.S. military opposed the agreement and deployed warplanes to bomb the road ahead of the ISIS convoy. Lt. Gen. Stephen Townsend, commander of the anti-ISIS forces in Iraq and Syria, said coalition jets also struck ISIS fighters and vehicles attempting to approach the convoy to link up with the evacuating militants.

Townsend made clear coalition forces did not directly target the convoy, which carried more than 300 ISIS fighters, many of whom were masked and armed with machine guns, along with some 300 family members.