Iran seized two ships in the Strait of Hormuz on Wednesday, tightening its grip on the strategic waterway, after US President Donald Trump called off attacks indefinitely with no sign of peace talks restarting.
Iran's semi-official Tasnim news agency said the Revolutionary Guards had seized two vessels for maritime violations and escorted them to Iranian shores. It was the first time Iran has seized ships since the war began at the end of February.
The Revolutionary Guard Corps Navy also warned that any disruption to order and safety in the strait would be considered a "red line", Tasnim said.
Earlier, a British maritime security agency reported that three ships had come under fire.
Trump said in a statement on social media late on Tuesday that the US had agreed to a request by Pakistani mediators "to hold our Attack on the Country of Iran until such time as their leaders and representatives can come up with a unified proposal ... and discussions are concluded, one way or the other."
But even as he announced what appeared to be a unilateral ceasefire extension, Trump also said he would continue the US Navy's blockade of Iran's trade by sea. The US fired on and seized an Iranian cargo vessel on Saturday and boarded a huge Iranian oil tanker on Tuesday in the Indian Ocean.
Iran considers the US blockade an act of war and has said that as long as it continues it will not lift its closure of the strait, which has caused a global energy crisis.
In a show of defiance, Iran showcased some of its ballistic weapons at a parade in Tehran on Tuesday evening, with images showing a large banner in the background with a fist choking off the strait, the WANA news agency reported.
Captions read: "Indefinitely under Iran's Control" and "Trump could not do a damn thing", referring to the waterway.
PAKISTAN STILL WORKING TO FOSTER TALKS DESPITE 'SETBACK'
Pakistan, which has acted as a mediator, was still trying to bring the sides together for negotiations after both failed to show up for last-ditch talks on Tuesday before the two-week-old ceasefire had been due to expire.
A luxury hotel in Islamabad had been cleared out for the talks, but Iran never publicly accepted the invitation and the US delegation led by Vice President JD Vance never left Washington. The hotel was still shut on Wednesday but a wider security perimeter had been loosened.
"We were all prepared for the talks, the stage was set," a Pakistani official briefed on the preparations told Reuters. "If you ask me honestly, it was a setback we were not expecting, because the Iranians never refused, they were up to come and join, and they still are."
Another Pakistani source who was involved in the talks said Pakistan was still "working very hard to bridge that conflict, talk to each side with their sensitivities in mind".
"We will know later on when they can come. Things change so often it's hard to speak on what's to come," the source said.
There was no response early on Wednesday to Trump's ceasefire announcement from senior Iranian officials, although some initial reactions from Tehran suggested Trump's comments were being treated skeptically.
Tasnim said Iran had not asked for a ceasefire extension and repeated Tehran's threats to break the US blockade by force.
An adviser to Iran's lead negotiator, the speaker of parliament Mohammad Baqer Qalibaf, said Trump's announcement might be a ploy.
Just hours before Trump called off attacks, he had repeated threats to resume them, saying his military was "raring to go".