A drone strike targeted the United Arab Emirates’ Barakah nuclear power plant Sunday, setting an electrical generator ablaze on its perimeter and again straining the shaky ceasefire in the Iran war.

No one immediately claimed responsibility for the attack, which caused no radiological release nor injuries, authorities in the UAE’s capital, Abu Dhabi, said. However, suspicion immediately fell on Iran, which has been increasingly threatening the UAE over recent days as the country hosted Israeli Iron Dome missile defenses and troops during the war.

The attack comes as Iran still has a chokehold on the Strait of Hormuz, a vital waterway where a fifth of the world’s oil and natural gas passed through before the war, disrupting global energy supplies. Meanwhile, America continues to block Iranian ports in response as negotiations to solidify the ceasefire have failed to advance.