An Iranian flotilla stopped a pirate attack on an Iranian merchant vessel in the Red Sea, the country's navy said on Friday.
It said Iran Navy vessels confronted “pirates in the Red Sea” in the incident on Thursday.
This is the second such incident in the stretch of water in less than a month.
“A suspicious boat with 12 armed people on board approached the Iranian merchant ship in Bab Al Mandeb,” state news agency Irna reported.
The Bab Al Mandeb strait connects the Red Sea to the Gulf of Aden.
When the flotilla, which was led by the Jamaran frigate, opened fire on the vessel, it left the area, Irna reported.
On August 10, a senior Iranian navy commander said the same naval flotilla thwarted an overnight attack on another Iranian vessel.
Admiral Mustafa Tajeddini said that, following a request for help by an Iranian ship in the Red Sea, the vessels were sent to the scene.
“After heavy exchanges, the attacking boats made off,” he said.
In November last year, pirates attempted to seize an Iranian oil tanker in the Gulf of Aden, Irna reported at the time.
Two weeks earlier, an Iranian warship repelled an attack by pirates against two oil tankers that it was escorting in the Gulf of Aden.
Iran seizes US sea drones
On Friday, Iranian state TV reported that the Jamaran had seized but later released two US unmanned vessels in the Red Sea on Thursday.
It said the sea drones were jeopardising maritime safety.
The report comes after the Pentagon said on Tuesday that an Iranian ship seized an unmanned US military research vessel in the Arabian Gulf.
"The [Iran Navy] frigate Jamaran seized the two vessels on Thursday to prevent any possible accident after issuing warnings to the US fleet," the Iranian state TV report said.
"After international shipping lanes were secured, the two vessels were released in a safe area."
Footage appeared to show more than a dozen Iran Navy personnel pushing two drones into the sea from the deck of their vessel.
Like other countries dependent on the shipping lane through the Red Sea and Suez Canal, Iran stepped up its naval presence in the Gulf of Aden after a wave of attacks by Somalia-based pirates between 2000 and 2011.