Iranian officials said Tehran has adopted new tactics to attack ships operating in the Strait of Hormuz without its permission.

Reuters reported on Wednesday that two senior Iranian officials confirmed Tehran had adopted the new strategy about ten days ago. “The aim is to frustrate efforts by the United States and its allies to bring ⁠down global oil prices,” one of the officials explained. 

The shift in tactics comes as Brent crude prices have climbed above $106 per barrel. The officials said the strategy was also intended to influence the US midterm elections in November by preventing President Donald Trump from bringing down oil prices.

“Just when they think they are getting close to the point where prices will fall, we will push them away from it. This is a game of chess,” the second official said. “Such vessels would be safe nowhere, even outside the Strait of Hormuz.”

A US military official also told the outlet that Iran had shifted tactics and started using unarmed spotters on small vessels to identify potential targets, including US warships.

The Strait of Hormuz has become a major issue in the war. Before the war, the Strait operated as an international shipping route. After the US and Israel attacked Iran, Tehran asserted control over shipping through the waterway and imposed new transit protocols. 

Iran has attacked vessels attempting to use the waterway without Tehran’s permission. As a fifth of the global oil supply exits the Persian Gulf through the Strait, the US has escorted tankers through the waterway to keep oil prices from spiking. 

One Iranian official said Tehran would soon prevent any vessel that violates its protocols from transiting the Strait. “It will be complete closure soon,” they said.