A drone strike caused a fire at a nuclear power plant in the ​United Arab Emirates, officials there said on Sunday, while Saudi Arabia reported intercepting three drones, as US President Donald Trump warned that Iran must act “fast” after efforts to ‌end the US-Israeli war with Iran appeared to have stalled.

Emirati officials said they were investigating the source of the strike and that the UAE had the full right to respond to such “terrorist attacks.”

A diplomatic adviser to the UAE president said it represented a dangerous escalation, whether carried out by “the principal perpetrator” or one of its proxies.

The UAE defence ministry said two other drones had been “successfully” dealt with, and that the drones had been launched from the “western ​border.” It did not elaborate.

Saudi Arabia said the three drones it intercepted entered from Iraqi airspace and warned that it would take the necessary operational measures to respond to ​any attempt to violate its sovereignty and security.

While hostilities during the Iran conflict have largely been scaled down since a ceasefire came into effect ⁠in April, drones have been launched from Iraq towards Gulf countries, including Saudi Arabia and Kuwait.

The drone that got through the UAE’s defences hit an electrical generator outside the inner perimeter of the Barakah ​Nuclear Power Plant, the Abu Dhabi Media Office said.

Radiological safety levels were unaffected and there were no injuries, it said.

UAE’s Federal Authority for Nuclear Regulation later confirmed that the plant remained safe, ​with no radioactive material released from the strike.

The International Atomic Energy Agency said emergency diesel generators were providing power to the plant’s “unit 3,” and called for “maximum military restraint” near any nuclear power plant, adding that it was following the situation closely.

During the war that began with US and Israeli strikes against Iran on February 28, Iran has repeatedly targeted the UAE and other Gulf states that host US military bases, hitting sites that include civilian ​and energy infrastructure.

Iran stepped up such attacks on the UAE earlier this month after Trump announced a naval mission to try to open the Strait of Hormuz, which Trump suspended after 48 hours.