A Danish warship has attacked a pirate boat in Somalian waters, killing four pirates and freeing 16 Iranian hostages on board, Denmark's navy said Sunday.

Ten other pirates were also wounded during gun battles between the Danish vessel Esbern Snare and the pirate "mother-ship" off Somalia on Thursday.

"The 16 hostages are waiting to see their families," the navy said in statement.

"None of them and no one among the crew of the Esbern Snare was wounded," it said>.

"All the hostages are doing well given the circumstances," Kenneth Nielsen, the navy's chief of staff spokesman, told TV2 News.

The 24 captured pirates are still on board the warship as Danish authorities consider criminal proceedings.