The International Atomic Energy Agency says it has now assessed that Israel’s strikes on the Khondab heavy water research reactor damaged key buildings at the facility, including the distillation unit, Al Jazeera reports.

But the global nuclear watchdog says that because the Khondab reactor was still under construction and not operational, it contained no nuclear material. Therefore, no “radiological consequence” was expected, the agency’s head Rafael Grossi said in a statement.

The statement said that damage to the facility — which was previously named Arak — had initially not been visible, but that the agency had later assessed that key buildings in the complex had been damaged.

The Israeli military said that it had specifically targeted “the structure of the reactor’s core seal, which is a key component in plutonium production”.