1053 GMT June 19, 2019
The UAE said on Sunday that four commercial vessels were sabotaged near Fujairah emirate, one of the world's largest bunkering hubs lying just outside the Strait of Hormuz.
Fujairah port is the only Emirati terminal located on the Arabian Sea coast, bypassing the Strait of Hormuz, through which most Persian Gulf oil exports pass.
Neither Saudi Arabia nor the UAE gave details on the nature of the attacks.
Shortly after the Saudi announcement, Iran's Foreign Ministry called for further clarification about what exactly happened with the vessels.
Foreign Ministry spokesman Seyyed Abbas Mousavi on Monday called the incidents "worrisome and dreadful" and asked for an investigation into the matter.
"The incidents in the Sea of Oman are alarming and regrettable," Mousavi said.
He said there should be more information about the incident.
He "warned against plots by ill-wishers to disrupt regional security" and "called for the vigilance of regional states in the face of any adventurism by foreign elements," it added.
Mousavi said the incident "has a negative impact on maritime transportation security."
A senior Iranian lawmaker said "saboteurs from a third country" could be behind it.
"The explosions of Fujairah port could have been carried out by saboteurs from a third country who seek instability in the region," said Heshmatollah Falahatpisheh, the head of the Iranian Parliament’s National Security and Foreign Policy Committee.
A fifth of global oil consumption passes through the Strait of Hormuz from Middle East crude producers to major markets in Asia, Europe, North America and beyond.
On Monday, US benchmark crude oil added 78 cents to $62.44 per barrel in electronic trading on the New York Mercantile Exchange. Brent crude, the international standard, gained $1.14 to $71.76 per barrel.
Saudi Energy Minister Khalid al-Falih said in a statement that one of the two Saudi vessels attacked was on its way to be loaded with Saudi crude from Ras Tanura port for delivery to state-owned Saudi Aramco's customers in the United States.
The attack did not lead to any casualties or an oil spill but caused significant damage to the vessels' structures, he said.
Falih said the attack aimed to undermine maritime freedom and the security of oil supplies to consumers worldwide.
"The international community has a joint responsibility 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," he said.
INTERTANKO, an association of independent tanker owners and operators, said in a note that it has seen photos showing that "at least two ships have holes in their sides due to the impact of a weapon."
Trading and shipping sources identified the Saudi vessels as Bahri-owned very large crude carrier (VLCC) tanker Amjad and crude tanker Al-Marzoqah.
The UAE Foreign Ministry has said there were no casualties and the Fujairah port operations were normal. An investigation had been launched in coordination with international authorities, it said, calling on global powers to prevent any parties trying to harm maritime safety and security.
Persian Gulf stock markets fell on Monday, with Dubai down 2.6% and the Saudi index down over 2%.
Reuters, AP and AFP contributed to this story.