April 22 (UPI) — An Iranian gunboat attacked and badly damaged a container ship close to the Strait of Hormuz on Wednesday with a second cargo vessel fired on, Britain’s maritime security agency said.

The master of an unidentified container ship reported that the vessel was in the western approaches to the strait, about 15 nautical miles off the coast of Oman when an Islamic Revolutionary Guard Corps gunboat approached and opened fire without warning, the Royal Navy’s Maritime Trade Operations center said in an alert.

The ship sustained “heavy damage to the bridge” but there was no fire or environmental impact and the crew was safe.

No attempt to make VHF radio contact was made before the gunboat fired on the vessel, said UKMTO.

There were no details or information regarding the ship, but CBS News said it was the Greek-owned Epaminondas.

An IRGC-linked news outlet said that the container ship was attacked because it “ignored the warnings of the Iranian armed forces.”

In the second incident, which occurred about 8 nautical miles west of the coast of Iran, the master of a cargo ship reported being fired on but there was no information as to who may have been responsible.

There was no damage, but the attack brought the vessel to a stop and it remains stationary.

“Crew are safe and accounted for,” UKMTO said.

“UKMTO is aware of high levels of activity in the SoH area and encourages vessels to report any suspicious activity,” the agency added.

The BBC said the cargo ship was the Panama-flagged container ship, Euphoria, which is owned by a United Arab Emirates company, and that it was en route to Jeddah in Saudi Arabia.

The IRGC-affiliated Fars news agency confirmed the attack, saying the Euphoria was now grounded off the coast of Iran.

Maritime intelligence firm Vanguard told the BBC that a third vessel, the Panama-flagged MSC Francesca, sailing outbound from the Persian Gulf had been attacked and damaged 6 nautical miles off the coast of Iran.

The company said the container ship’s hull and accommodation decks were damaged when it was interdicted by the IRGC and “instructed to drop anchor” as it was headed eastwards out of the Hormuz Strait into the Gulf of Oman.

The IRGC Navy said in a statement that it had “seized” both the Epaminondas and the MSC Francesca and was escorting them toward the Iranian coast.

The attacks came hours after U.S. President Donald Trump announced an indefinite extension to a cease-fire with Iran that had been due to expire on Wednesday but that the United States’ blockade of Iranian ports would remain in place.

The naval blockade, which began April 13, saw a U.S. warship open fire on an Iranian container ship in the Gulf of Oman on Sunday before U.S. marines boarded and seized the vessel.

Oil prices, which had fallen on the news of the cease-fire extension, rose Wednesday with the international benchmark Brent crude contract again testing the $100 a barrel ceiling in late-morning trade in London while West Texas Intermediate was changing hands at $90.21, up 54 cents a barrel.