MADRID — Spain ruled out freeing two captured pirates as demanded by fellow brigands holding a Spanish trawler and 33 crew members off Somalia and reportedly threatening to start killing hostages.

Deputy Defense Minister Constantino Mendez said Friday the two Somali men were captured and brought to Madrid because of their alleged role in the hijacking of a Spanish-flagged vessel — the tuna boat Alakrana, on Oct. 2 in the Indian Ocean.