A U.S. military convoy was seen driving and stopping near the Gweiran Prison in Hassakeh in northeastern Syria on Tuesday.

A U.S. Chinook helicopter was also seen landing near the prison by the time the convoy was stopping.

The prison was the focus of a furious battle recently between U.S.-backed, Syrian Kurdish-led forces and militants from the Islamic State group.

On Jan. 20, around 200 militants attacked the prison, in coordination with a riot by inmates inside.

The attackers broke in, freed some prisoners, took guards hostage, and held out against fighters from the Syrian Democratic Forces (SDF) for days, even as aircraft from the U.S.-led coalition struck their positions repeatedly.

The battle for Gweiran Prison took 10 days, but the Kurdish-led forces finally defeated the militants who attacked the facility in Hassakeh, aiming to break free their comrades jailed inside, in the group’s largest and most stunning operation in years.

At least 121 SDF fighters and prison guards and more than 380 militants were killed before the SDF finally restored full control.

IS suffered a blow with the U.S. raid last week in northwest Syria that killed the group’s leader, Abu Ibrahim al-Hashimi al-Qurayshi.

AP