The UAE's defence ministry said the drone that targeted the facility was one of three that "entered the country from the western border direction".
The projectile struck "an electrical generator outside the inner perimeter of the Barakah Nuclear Power Plant in the Al Dhafra area".
"Investigations are ongoing to determine the source of the attacks, and updates will be disclosed upon completion of the investigations," the ministry added.
UAE presidential adviser Anwar Gargash appeared to refer to Iran and its regional proxy groups in his condemnation of the attack.
"The terrorist targeting of the Barakah clean nuclear power plant, whether carried out by the principal perpetrator or through one of its agents, represents a dangerous escalation," he wrote on X.
He called the incident "a dark scene that violates all international laws and norms", accusing the perpetrators of a disregard for the lives of civilians in the UAE.
Iranian-backed armed groups equipped with drones are based in Iraq, while Tehran's allies in Yemen, the Houthi rebels, also possess combat-grade UAVs.
The UAE "condemned in the strongest terms the unprovoked terrorist attack" and "will not tolerate any threat to its security and sovereignty under any circumstances", a foreign ministry statement said.
"These attacks constitute a dangerous escalation, an unacceptable act of aggression and a direct threat to the country's security," it added.
The $20 billion Barakah Nuclear Power Plant was built by the UAE with the help of South Korea and began operations in 2020 and is 200 kilometres (120 miles) west of the UAE's capital Abu Dhabi, near the borders with Saudi Arabia and Qatar.
It is the only nuclear power plant in the Arab world and provides up to a quarter of the oil-rich country's electricity needs, the state-owned operator Emirates Nuclear Energy Company said in 2024.
The UAE signed a strict deal with the US over the nuclear power plant, known as a “123 agreement,” in which it agreed to forego domestic uranium enrichment and reprocessing of spent fuel to ease any proliferation concerns. Its uranium comes from abroad.
That's very different from the nuclear program in Iran that is at the heart of long-running tensions with the United States and Israel.
"No injuries were reported, and there was no impact on radiological safety levels," the Abu Dhabi Media Office said. "All precautionary measures have been taken, and further updates will be provided as they become available.
"The Federal Authority for Nuclear Regulation (FANR) confirmed that the fire did not affect the safety of the power plant or the readiness of its essential systems, and that all units are operating as normal."
Sporadic attacks
An official from the Korea Electric Power Corporation (KEPCO), which operates the Barakah plant, said there were no casualties, and the plant had not been damaged.
"It does not appear that there was a direct attack on the nuclear plant we manage and operate. It seems a fire broke out at other power facilities on the outskirts," the official said, quoted by the Yonhap news agency.
"In the case of one reactor, operations were briefly halted as a precaution to ensure safe operation," the KEPCO official added.
Rafael Grossi, the head of the UN's nuclear agency, condemned the attack.
The International Atomic Energy Agency said in a social media post that Grossi expressed "grave concern about the incident and says military activity that threatens nuclear safety is unacceptable".
UAE FM Abdullah bin Zayed Al Nahyan has held a phone call with IAEA chief Rafael Grossi following the drone attack on the country’s nuclear facility, according to the UAE news agency WAM.
He told Grossi that his country has the full right to respond to “terrorist attacks” following a drone attack on the Barakah nuclear power plant.
The United Arab Emirates was the second country in the region to build a nuclear power station, after Iran, and the first in the Arab world.
The Abu Dhabi statements did not say from where the drone was launched, but the United Arab Emirates has recently accused Iran of being behind attacks on its energy and economic infrastructure.
Tehran launched retaliatory strikes across the region after the United States and Israel struck Iran on February 28, killing senior leaders and triggering a broader war.
Iran has accused the UAE and other US allies in the Gulf of allowing US forces to carry out attacks from their territory.
The UAE has angrily denied Iranian reports that it has actively carried out attacks of its own.
Washington and Tehran agreed to a truce on April 8, but peace negotiations have stalled, and sporadic attacks have continued.
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