Twenty suspected Somali pirates nabbed by the Dutch navy in the lawless waters off the restive Horn of Africa nation and the Seychelles coast have been freed, the defence ministry said.
"There were still 20 pirates on the Tromp frigate and they have been freed," ministry spokesman Marloes Visser told AFP yesterday.
The pirates were interrogated, disarmed and then allowed to board their vessels, he said, adding that the weaponry included assault rifles, rocket launchers and knives.
The Dutch navy, which is taking part in an European Union anti-piracy mission off the Somali coast, this week arrested 33 pirates travelling on nine vessels. Thirteen of them were freed on Wednesday.
"They had weapons used by pirates but that was not enough" to charge them, Visser said.
Since mid-2009, Somali pirates have ventured from the now heavily-patrolled waters of the Gulf of Aden to launch the bulk of their attacks much further out in the Indian Ocean.