Saudi Arabia announced on Monday that two of its oil tankers suffered “significant damage” from sabotage attacks off the coast of the United Arab Emirates (UAE) near the Strait of Hormuz. The attacks reportedly also damaged two ships from other nations, one of them registered to Norway.

The Saudis and Emiratis did not name any suspects but their implications about the motive suggested a link to Iran. Saudi Energy Minister Khalid al-Falih said the sabotage was intended to “undermine the freedom of maritime navigation, and the security of oil supplies to consumers all over the world.”

The minister’s statement stressed the responsibility of the international community to “protect the safety of maritime navigation and the security of oil tankers, to mitigate against the adverse consequences of such incidents on energy markets, and the danger they pose to the global economy.”

Heshmatollah Falahatpisheh, the head of Iran’s parliamentary national security committee, fired back on Monday by suggesting “saboteurs from a third country” were responsible, implying the ships were attacked by American agents seeking to create an excuse for military action against Iran.

“The explosions of Fujairah port could have been carried out by saboteurs from a third country who seek instability in the region,” Falahatpisheh said.

The Iranian lawmaker was referring to reports in Iranian and Lebanese media of explosions and fires at the port facility in Fujairah. The UAE Foreign Ministry dismissed these reports on Sunday as “baseless and unfounded.”

A spokesman for the Iranian Foreign Ministry also warned about a “conspiracy orchestrated by ill-wishers” and “adventurism by foreigners” intended to undermine regional stability.

UAE authorities said on Monday the incident is still under investigation, but whatever occurred, the affected ships were anchored off the coast of the Emirates near the Strait of Hormuz when it occurred. Iran has threatened to close the Strait of Hormuz or attack ships passing through it to disrupt the world’s oil supply in retaliation for U.S. sanctions against Iranian oil.

The BBC on Monday relayed the first information about the incident to emerge from Saudi and Emirati media:

On Monday morning, the official Saudi Press Agency quoted the country’s energy minister, Khalid al-Falih as saying two Saudi oil tankers had been among the ships targeted. “One of the two vessels was on its way to be loaded with Saudi crude oil from the port of Ras Tanura, to be delivered to Saudi Aramco’s customers in the United States,” he added. Industry sources told the BBC that the Saudi tankers affected were the Amjad and Al Marzaqah. Saudi-based Al Arabiya TV aired what it said were the first images of the damaged ships on Monday. It reported that the other vessels targeted were from Norway and the UAE. A picture released by the UAE shows a Norwegian-flagged vessel, Andrea Victory, with damage to its hull. Thome Ship Management, a Norwegian firm which manages the ship, said in a statement that had been “struck by an unknown object on the waterline” while anchored off Fujairah. No crew members were harmed. Intertanko, an association of independent tanker owners and operators, said it had seen pictures showing that “at least two ships have holes in their sides due to the impact of a weapon”, Reuters news agency reported.

The U.S. Maritime Administration issued an advisory to sailors in the area but stressed the incident “has not been confirmed.” The agency warned last week that Iran and its proxies might “take action against U.S. and partner interests, including oil production infrastructure” by “targeting commercial vessels, including oil tankers.”