An Iranian gunboat fired at a container ship off the coast of Oman on Wednesday, causing damage but no casualties, a British maritime security agency said.

‘The master of a container ship reported that the vessel was approached by one IRGC gunboat that then fired upon the vessel, which has caused heavy damage to the bridge. No fires or environmental impact reported,’ the United Kingdom Maritime Trade Operations centre said.

It added that the incident took place 15 nautical miles northeast of Oman and all the crew were safe.

According to British maritime security firm Vanguard Tech, the vessel was sailing under a Liberian flag and ‘had been informed it had permission to transit the Strait of Hormuz’.

But Iranian news agency Tasnim said the ship had ‘ignored warnings from Iran’s armed forces’.

Shipping through the strategic Strait of Hormuz has been heavily restricted by Iran since the start of the war with Israel and the United States, while the US military is enforcing a blockade of Iranian ports.

US president Donald Trump announced Wednesday that the truce between the two countries would be extended after it first took effect on April 8.