Lagos, Nigeria (CNN) -- Nigerian gunmen on Sunday released 12 sailors who ship was attacked two days earlier off the country's coast, a spokesman for the Nigerian military said.
Pirates had boarded a German-flagged ship off the coast of Nigeria on Friday night and took the foreigners hostage, the country's military said.
The attack took place about four nautical miles off Bonny Island, said Lt. Col. Timothy Antigha of the military Joint Task Force (JTF) in the Niger Delta. He didn't release any details on the pirates, only saying they are "criminals."
One sailor was wounded in the attack and left on the boat, he said.
The kidnappers later abandoned the ship and it was retrieved by the Nigerian navy. The freed sailors were on their way to Bonny Island, where their ship is currently anchored off the coast of the southern Nigerian state of Rivers.
Earlier, Antigha had said he did not know the nationalities of the abducted sailors or whether the pirates had demanded a ransom.