(CNN) -- Somali pirates released a Philippine tanker and its 23 crew Tuesday -- five months after the ship was seized in the Gulf of Aden.
A statement from the Philippine's Department of Foreign Affairs did not say whether the pirates were paid a ransom for freeing the MT Stolt Strength.
The ship was hijacked on November 10 as it sailed from Senegal to India.
Pirates are still holding about 85 Filipino crew from several ships, including three aboard the Belgian-owned Pompei, which was seized in April 2008, the department said.
Piracy is rampant in the area, with vessels seized regularly and often released only after a large ransom is paid.
Securing the region is difficult. The area involved off the coasts of Somalia and Kenya, including the Gulf of Aden, is more than 1.1 million square miles -- four times the size of the state of Texas. See an interactive map of 2009 pirate attacks off the Horn of Africa »
At any given time, a number of nations could be in the region to protect the seas. Though the countries try to coordinate efforts, there are limits to the extent of information they share.