The suspected pirates were removed from a skiff by Dutch sailors
A group of suspected Somali pirates detained on a Dutch warship has been released because no country has agreed to prosecute them.
A Dutch defence ministry statement said the European Union had decided that the 13 detainees had to be freed because it was impossible to bring charges.
The suspects were seized in the Indian Ocean two weeks ago after allegedly attempting to attack a cargo ship.
They were put back on their own speedboat with some food and fuel.
They had been on board the Dutch warship Evertsen since early December after they were tracked down following the alleged attack on the Antigua and Barbuda-flagged cargo ship MV BBC Togo failed.
Regret at release
The European Union naval force said ladders, grappling hooks, nine automatic weapons, grenades and other ammunition were found on board their skiffs.
"The European Union has tried in vain since their arrest to find a country which would agree to prosecute them," the defence ministry statement said.
"The defence ministry regrets that the European Union has not found a suitable solution," the statement added.
Although the EU had signed agreements with the Seychelles and Kenya to help press charges against suspected pirates, "the two countries indicated they did not want to prosecute the pirates", the ministry said.
Differences over laws concerning the arrest of pirates have hampered efforts to curtail piracy in the Gulf of Aden.
There has been just a handful of pirate prosecutions outside Africa.
Warships from around the world are patrolling the Indian Ocean to try to fend off attacks in some of the world's busiest shipping lanes.
Somalia has not had an effective government since 1991 and the lawlessness has spread from land to the water in recent years.