Saudi Arabia has said two of its oil tankers were sabotaged off the coast of the United Arab Emirates (UAE) in attacks that caused "significant damage" to the vessels, one of them as it was en route to pick up Saudi oil to take to the US.
A total of four ships from different countries are reported to have been sabotaged off the coast of the port city of Fujairah.
Saudi Arabia's energy minister Khalid al-Falih's comments about the damage came as the US warned ships that "Iran or its proxies" could be targeting maritime traffic in the region.
The US has deployed aircraft carrier the USS Abraham Lincoln and B-52 bombers to the Persian Gulf to counter what the US is calling a credible threat from Iranian forces.
There are no details about what that threat might be, or where the intelligence has come from, but the Pentagon confirmed last week that it was in response to signs of heightened Iranian readiness to conduct offensive operations.
Dr Aziz Alghashian is from the University of Essex and specialises in the politics of the Middle East.
“I don’t think it will reach a full-scale war.
"I think although these attempts will cease, the diplomatic efforts, and the diplomatic jostling and the diplomatic rivalry and the political rivalry between the United States and the gulf vis-à-vis Iran will continue and will not cease, and not only that, this will then embolden the rhetoric on many sides - on the Iranian side, on the gulf/Saudi/UAE side and as well as the United States."
The Strait of Hormuz is the only sea passage between the Persian Gulf and the open sea.
It is where a third of all oil at sea is traded and is 85 miles from the port where the two Saudi oil tankers were sabotaged in the UAE.
Iran has called the incident "worrisome and dreadful" and is demanding an investigation.