DUBAI, United Arab Emirates (AP) — Saudi Arabia said Thursday it was responding to an emergency involving an Iranian oil tanker off the coast of Jiddah, and analysts said the vessel carried over 1 million barrels of fuel oil and might be leaking.

There was no immediate report on the incident in Iran, which suffered an oil tanker disaster last year in the East China Sea that killed 32 sailors and now faces a U.S. pressure campaign over its oil sales.

Saudi Arabia’s state-run television channels and news agency said authorities received a distress call from the Happiness I over an “engine failure and the loss of control.”

The vessel had a crew of 26, including 24 Iranians and two Bangladeshis, Saudi state media said. They described the ship’s position as some 70 kilometers (44 miles) south of Jiddah in the Red Sea.

Saudi authorities said various government agencies were involved in the operation, including those who handle environmental protection. It did not elaborate on whether oil had spilled from the tanker.

The website TankerTrackers.com, whose analysts monitor oil sales on the seas, estimated the Happiness I carried at least 1.1 million barrels of fuel oil. It said the ship sailed in tandem with another smaller sister ship named the Sabiti.

The Happiness I stopped its engines Tuesday, then was shadowed by the Sabiti close enough to have its crew escape, TankerTrackers said. Two tugboats from Saudi Arabia appeared to have reached the ships, TankerTrackers said.

TankerTrackers said an oil leak was possible on the Happiness I, though it gave no details.

“We cannot conclude what caused the leak, but given how abruptly things happened, it does seem like something surprised them otherwise we would have seen the vessels slow down or deviate in an attempt to avoid an incident,” the website said.

Saudi Arabia and Iran are chief Mideast rivals. Iran now faces increased pressure from the U.S. over its oil sales after President Donald Trump pulled America out of its nuclear deal with world powers. Iran has warned it will respond aggressively to any attempt to cut its oil exports to zero, as the Trump administration has pledged to do.

In January 2018, the Iranian oil tanker Sanchi struck the Chinese freighter CF Crystal 257 kilometers (160 miles) off the coast of Shanghai in the East China Sea. The Sanchi, carrying nearly 1 million barrels of a gassy, ultra-light oil bound for South Korea, burst into flames.