On Sunday, a drone attack sparked a fire on the outskirts of the United Arab Emirates’ sole nuclear power plant, highlighting the risk of renewed hostilities as the United States and Iran signaled their readiness to go to war again.

The UAE Ministry of Defense said that three drones flew over its western border with Saudi Arabia, while two others were intercepted. It is investigating who launched them.

The $20 billion Barakah nuclear power plant was built by the UAE with assistance from South Korea and began operations in 2020. It is the only nuclear power plant in the Arab world and can meet a quarter of the UAE’s energy needs.

The UAE’s nuclear regulator stated that the fire did not affect the safety of the nuclear power plant and that all systems are operating normally.