Nearly a dozen pirates armed with rocket-propelled grenades, machineguns and grappling hooks have been seized in the Gulf of Aden, after being intercepted by a British Royal Navy warship.

Two skiffs had been detected by the radar on board HMS Portland, a Type 23 frigate, which was originally designed for anti-submarine warfare.

Suspecting that they were “not innocent fishing vessels,” the frigate, led by Commander Tim Henry, steamed closer to the skiffs and saw that both vessels were filled with weaponry and ammunition. The ship’s Lynx helicopter was sent to hover over the skiffs while teams of Royal Marine and navy personnel in rigid inflatable boats sped towards the craft and disarmed the 10 men on board. The Lynx was armed with a machinegun and snipers.

“The skiffs were equipped with extra barrels of fuel, grappling hooks and a cache of weapons that included rocket-propelled grenades, machineguns and ammunition,” navy officials said.

Because of the rules of engagement, however, the pirates had to be set free. “We can only arrest suspected pirates if we catch them in the act or on the point of launching an attack on a vessel,” a Ministry of Defence official said.

“Clearly, with all the weaponry in the skiffs, there was an intent to commit piracy, but we hadn’t actually caught them in the middle of an attack so we had to release them.”

All the weapons and ammunition were confiscated and the 10 men were piled into the larger of the two skiffs, provided with enough fuel to get them to the Somali coast and told to go home. Some of the fuel was then put into the other skiff and set on fire.

“The pirates tend to use the smaller boats to go up against the merchant vessels they are trying to hijack, so we basically removed or destroyed all the piracy paraphernalia,” the MoD official said.

HMS Portland is serving with the Combined Maritime Forces Task Force 151, a multinational naval group that currently consists of ships from the United States, Britain, Turkey, South Korea, Singapore, Denmark and Japan. It was established to conduct counter-piracy operations.

Click here to read more on this story from the Times of London.