They retreated to Bin Jawad, 12 miles from Nawfailyah, before getting back on the road, only to face further clashes with Gaddafi forces.
The rebel unit was ambushed from high ground, coming under fire from small arms, light mortars and rocket propelled grenades.
Rebel fighters waiting on the open desert road leapt behind dunes and mounds of earth and shot at the Gaddafi troops as they arrived.
As the onslaught grew, the rebels ran to their pickup trucks and sped off down the road to Bin Jawad, about 93 miles east of Gaddafi's home town of Sirte.
Bullets zipped overhead and shells landed on and near the road as they retreated.
Gaddafi forces appeared to end their attack several miles west of Bin Jawad and the rebels stopped in the town to wait and regroup.
The rebel fighters had raced along the coastline retaking several oil towns after Western warplanes began air strikes on Gaddafi positions in the east and west of the desert country on March 19.