A fourth tanker was a target of the sabotage that embroiled two Saudi and one Norwegian oil tankers, Reuters reported late on Monday, this time bearing the flag of the United Arab Emirates.

Earlier in the day, the UAE had reported that three tankers had been the subject of sabotage off its coast, but did not offer any additional details as to the nature of the attacks. Saudi Arabia has also not commented on the nature of the attacks, but said that the damages were “significant”.

The Strait of Hormuz is a critical chokepoint for the oil trade, which Iran has threatened to close off should the US be successful at restricting its oil exports. Iran—enjoying a rather adversarial relationship with both Saudi Arabia and the UAE—chastised its fellow OPEC members for promising to ramp up production to ensure a well-supplied market as needed should Iran’s oil customers want it. Iran accused Saudi Arabia and the UAE of wielding their oil as a weapon.

The third tanker the subject of sabotage was Norway’s. Norway said its tanker was struck with an unknown object, leaving a hole in the hull of its ship. The ship management company said the blow nearly caused the tanker to sink.

The sabotage, which has been revealed to now include four tankers, has increased tensions in the Middle East at a time when oil prices seem to be at the mercy of such geopolitical goings on, with quiet fingers being pointed at the likely suspect, Iran. Officials have stopped short of blaming Iran for the attacks in the absence of any evidence.

US Central Command said it is helping to investigate the matter of sabotage at the UAE’s request.

By Julianne Geiger for Oilprice.com

More Top Reads From Oilprice.com: