A suspected hijacking of a vessel near Iran has ended, the British Navy said Wednesday, days after a deadly drone attack on a tanker in the same area that the U.S and its allies blamed on the Islamic Republic.

The events have stoked tensions in and around the waterways of the Persian Gulf, through which many of the world’s oil exports are carried.

The U.S. has vowed a “collective response” to last week’s strike on an Israeli-operated vessel, which killed a Romanian and a Briton, as Tehran denied involvement. On Wednesday, Iran’s Islamic Revolutionary Guard Corps warned it would react “decisively and powerfully” to any provocation. Shipping attacks have escalated in recent years amid tensions between Iran and the U.S. and its Israeli ally but fatalities are unusual.

The Panama-flagged Asphalt Princess was temporarily hijacked on Tuesday when it was roughly halfway between Iran and the United Arab Emirates in the Gulf of Oman, according to a Gulf government official. Armed men boarded the vessel and then left around midnight local time, the official said. Bloomberg was unable to contact the ship’s Dubai-based owner or operator to confirm the information.

The incidents come at a sensitive time for the region and Iran, which confirmed an ultraconservative new president on Tuesday and is weighing when to reenter stalled talks with world powers over its controversial nuclear program the West believes could help deliver Tehran a bomb. The U.S. wants to engage in diplomacy and is seeking to renter a 2015 nuclear deal that would limit the atomic work in return for sanctions relief.