Dutch commandos freed 20 Yemeni hostages today and briefly detained seven pirates who had forced the Yemenis to sail a "mother ship" attacking vessels in the Gulf of Aden, Nato officials said.
In a separate incident, gunmen from Somalia seized a Belgian-registered ship and its 10 crew, including seven Europeans, further south in the Indian Ocean.
"The Pompeiis heading slowly towards the Somali coast," Peter Mertens, a spokesman for a Belgian government crisis centre, said. "We have had visual contact from a helicopter of a Spanish navy ship."
Somali sea gangs have captured dozens of ships, taken hundreds of sailors prisoner and made off with tens of millions of dollars in ransoms despite an unprecedented deployment by foreign navies in waters off the Horn of Africa.
The attacks have disrupted UN aid supplies, driven up insurance costs and forced some shipping companies to route cargo round South Africa, rather than risk approaching Somalia.
Nato Lieutenant Commander Alexandre Fernandes, speaking on board the Portuguese warship Corte-Real, said the 20 fishermen were rescued after a Dutch navy frigate on a Nato patrol responded to an assault on a Greek-owned tanker by pirates firing assault rifles and grenades.
Commandos from the Dutch ship, the De Zeven Provincien, pursued the pirates, who were on a small skiff, back to their "mother ship," a hijacked Yemeni fishing dhow.
"We have freed the hostages, we have freed the dhow and we have seized the weapons... The pirates did not fight and no gunfire was exchanged," Fernandes told Reuters. The Corte-Real is also on a NATO anti-piracy mission.
He said the hostages had been held since last week. The commandos briefly detained and questioned the seven gunmen, he told Reuters, but had no legal power to arrest them.
"Nato does not have a detainment policy. The warship must follow its national law," he said.
"They can only arrest them if the pirates are from the Netherlands, the victims are from the Netherlands, or if they are in Netherlands waters."
He said an unexploded rocket-propelled grenade was later found on board the tanker, the Marshall Islands-flagged MT Handytankers Magic, managed by Roxana Shipping SA of Greece.
Mr Mertens said fears grew for the Pompei, a dredging vessel, after it sounded two alarms early on Saturday when it was about 600 km from the Somali coast en route to the Seychelles.
The ship was carrying two Belgian, four Croatian, one Dutch and three Filipino crew members.
A pirate source who said he was on board the Pompeitold Reuters in Mogadishu by satellite phone that the pirates would sail it to a coastal base. "We have hijacked a Belgian ship. We will take it to Haradheere," he said.
Mr Mertens said the Spanish Navy ship that sent the helicopter would probably make visual contact with the "Pompei" around 2000 GMT (9pm Irish time) today, but did not have any special forces on board that could recapture the Belgian ship.
Reuters