Nine suspected Somali pirates have been captured by the French navy and handed over to regional officials in northern Somalia, the authorities there say.
Patrolling French marines arrested the pirates in the Gulf of Aden after intercepting two boats on Wednesday, officials in Puntland said.
It comes as the International Maritime Bureau said the waters off Somalia were the world's worst for pirate attacks.
Pirates believed they can act with impunity, the monitoring agency said.
Nato ships are expected in the region in the coming days to escort aid ships through the dangerous waters.
But a spokesman said a precise time for the fleet's arrival could not be given because of delays caused by a violent storm that has sunk boats and killed livestock in northern Somalia.
The crew of a French warship picked up the suspected pirates and handed them over to the authorities in semi-autonomous Puntland on Wednesday, Puntland's presidential adviser Bile Mohamoud Qabowsade said.
He said eight suspects had been caught, although other reports put the figure at nine.
"The pirates were on board two small boats when the French military arrested them. They dropped all their weapons in the water before they were caught," Puntland's deputy Fisheries Minister Abdukadir Muse Yusuf was quoted as saying by AFP news agency.
Many pirates are based in the Puntland town of Eyl. The authorities there had been accused of turning a blind eye but have recently stormed two ships seized by pirates and freed the crew.
France has launched two operations already this year to free French ships and crew seized by Somali pirates.
Pirates are still holding the Ukrainian ship, the MV Faina, and its cargo of tanks and military hardware, off the Somali coast. They demand $20m (£12m).
The International Maritime Bureau (IMB) said on Thursday that 63 of 199 incidents of piracy worldwide recorded in the first nine months of this year had taken place off east Somalia and the Gulf of Aden.
This was double the 36 attacks blamed on Somali pirates out of 198 worldwide in the same period last year, the bureau added.
"Piracy attacks off the coast of Somalia are unprecedented," said IMB director Pottengal Mukundan. "It is clear that pirates in the Gulf of Aden believe that they can operate with impunity in attacking vessels."
He said the extension of attacks from eastern Somalia into the Gulf of Aden now threatened a vital trade route between Asia and Europe.
International naval forces patrolling the region must take greater action to prevent future attacks, he said.
"What is required is robust action against the pirates' mother ships before they succeed in hijacking vessels," he said. "The locations and descriptions of these mother ships are known."
The flotilla of seven Nato frigates and destroyers is due in the area "sometime in the next four or five days", a spokesman said.
He said the fleet will then split, with three or four carrying on with their original plan to conduct exercises with the Gulf States, while the rest continue to Somalia.
The ships will escort World Food Programme ships carrying aid into Somalia, and provide a general deterrent.
Chief Nato spokesman James Appathurai said the crew would have a "full range of self-defence" measures at their disposal, including the "use of force". But he admitted "what they are trying to do is complicated".
"There are a host of pirates, but they don't identify themselves with eye-patches and hook hands so it isn't immediately obvious that they are pirates."
He said the rules of engagement should be agreed and finalised in the next day or two.