Three US Army troops were killed and at least two dozen service members were injured in a drone attack overnight on a small US outpost in Jordan, US officials told CNN, marking the first time US troops have been killed by enemy fire in the Middle East since the beginning of the Gaza war, Paralel.Az reports citing CNN.

The killing of three Americans at Tower 22 in Jordan near the border with Syria is a significant escalation of an already-precarious situation in the Middle East.

US Central Command confirmed in a statement on Sunday that three service members were killed and 25 injured in a one-way drone attack that “impacted at a base in northeast Jordan.”

As of Friday, there had been more than 158 attacks on US and coalition forces in Iraq and Syria, though officials have described the constant volley of drones, rockets, and missiles as unsuccessful as they have frequently not caused serious injury or damage to infrastructure.

It’s unclear why air defenses failed to intercept the drone, which appears to be the first known attack on Tower 22 since attacks on US and coalition forces began on October 17. US forces at the outpost are there as part of an advise-and-assist mission with Jordan.