Somali pirates released the Sinar Kudus, an Indonesian-flag multipurpose vessel, and its 20 crew members on Sunday after 46 days in captivity, according to Navfor, the EU anti-piracy naval force.
"The ship is now sailing to a safe port," Navfor said in a statement.
Navfor did not give any other details about the ship's release, but local reports said the ship owner paid a ransom of $4.5 million.
The 8,911-deadweight-ton Sinar Kudus, owned by Jakarta-based shipping group PT Samudera Indonesia, was hijacked on March 16 about 320 nautical miles northeast of the Socotra Islands in the Gulf of Aden as it sailed from Indonesia to Rotterdam.
According to earlier reports, the pirates had immediately used the Sinar Kudus as a mother ship to launch an attack on the Liberian-registered bulk carrier MV Emperor.
Separately, Navfor said pirates captured a Singapore-flag product tanker with 25 men on board off the coast of Kenya in the Somali Basin.
The 20,989-dwt. MV Gemini, operated by Singapore-based Glory Ship Management, was sailing from Kuala Tanjung (Malaysia) to Mombasa when it was seized April 30 some 180 nautical miles east of Malindi.
Navfor said it had no further information about the crew, and it was closely monitoring the situation.