The Danish military says the crew of one of its warships operating in West Africa killed four pirates in a shootout.
A statement said the frigate Esbern Snare, accompanied by a helicopter, approached a motorboat in southern Nigeria on Wednesday.
Onboard were eight men with ladders and other tools that pirates often used to board ships.
After the warning shots were ignored, the alleged pirates opened fire on Danish troops.
The military said four of the pirates died and one was injured; there were no Danish casualties.
Several countries have deployed ships to the region after more than 130 sailors were taken from vessels in the region last year.