The Iranian navy has fought off a pirate attack on two tankers in the Gulf of Aden.
The incident on Saturday involved a group of naval vessels including the Iranian destroyer Alborz, which was involved in a "heavy exchange of fire", according to state television.
The warship was escorting two tankers in a convoy, navy commander Admiral Shahram Irani told the official IRNA news agency.
"Navy commandos were successful in repulsing this morning the attack by pirates against an Iranian commercial convoy in the Gulf of Aden," he said.
"The destroyer Alborz was escorting two oil tankers when they were attacked by five pirate ships."
Shots fired from the destroyer forced the attackers to leave the area, Irani said.
Iran calls attack 'terrorism'
The naval chief called the incident "maritime terrorism". He said the two unnamed tankers passed safely through the area, which is now secure.
Iran's navy has extended the reach of its escort operations in recent years in an effort to protect its ships from Somali pirates.
Maritime security company Dryad Global said that, if confirmed, this would be the sixth reported suspicious approach in the region this year.
"Details regarding the incident remain sparse and thus it remains impossible to confirm piratical intent by the approaching vessels," Dryad added.
"Approaches against vessels transiting the Gulf of Aden remains the foremost reporting theme within the area; however, thus far there have been no incidents that have tangibly compromised vessel or crew safety."
Dryad believes the low volume of incident reports alongside an absence of persistent and sustained approaches, or attacks against smaller vulnerable vessels, would strongly indicate a low threat of piracy within the area.
But another security company, Diaplous Group, took a more serious view of the incident.
'High-risk' region
The company said the area of the Gulf of Aden up to the Red Sea, and particularly the Bab-el-Mandeb strait, is assessed as "high risk" due to increased tensions in the region.
"Rivalries between Yemen and Saudi Arabia have considerably affected security for vessels in the Red Sea, effectively providing convenient space for pirates to carry out their attacks," Diaplous said.
"Therefore, vessels sailing within this geographical area are highly advised to exercise extreme caution, and apply mitigation measures, where possible."
Iran itself has been accused by western powers of its own acts of aggression towards merchant shipping, especially those controlled by Israel of the UK, or flying their flags.
In July, a product tanker operated by Zodiac Maritime, which is controlled by Israeli tycoon Eyal Ofer, came under attack off the coast of Oman.
Two seafarers were killed in the incident.
The 49,992-dwt Mercer Street (built 2013) was involved in a "suspected piracy incident" when ballasting from Dar es Salaam to Fujairah, Zodiac said on Twitter.
The US said an Iranian drone had attacked the vessel, but Iranian officials blamed "Iranophobes" for the incident.
