BEIRUT — The two trucks raced toward the prison and then split up. One hurtled into the gates, the other the security wall, before both erupted in fireballs of metal and masonry. With the perimeter breached, other suicide attackers swarmed inside, toting weapons for themselves and the fellow jihadists they aimed to release. They remained barricaded inside for nearly a week until their defeat Wednesday by U.S.-backed fighters.
The assault by more than 100 Islamic State extremists on Ghweiran prison, a detention center in northeast Syria that holds thousands of their comrades, marked the most sophisticated attack the group has carried out since it was routed in the region almost three years ago — and could be a harbinger of its resurgence.
Ghweiran prison, on the edge of the city of Hassakeh, is the largest of 14 such detention facilities in the region under the control of the U.S.-backed Syrian Democratic Forces, or SDF. It houses more than 3,000 suspected fighters from Islamic State, also known as ISIS, as well as hundreds of boys, some as young as 10 — all of them crammed together in the buildings of a former engineering college.
