The European Union's anti-piracy force said Monday that pirates released a Japanese cargo ship, the MV Izumi, after four-and-a-half months of captivity. A statement said the vessel and its 20-member, all-Filipino crew were freed February 25 and are believed to be headed for a safe port.

The EU force also said pirates have seized a Greek-owned cargo ship off the coast of Oman, an area where Somali pirates have struck in the past. The MV Dover is said to have 23 crew members on board, including 19 Filipinos, three Romanians and one Russian.

Meanwhile, Denmark's foreign ministry said Monday that pirates have captured a yacht carrying seven Danish nationals, three of them children. It says pirates hijacked the yacht in the Indian Ocean late last week and are now sailing it toward Somalia.

Earlier this month, Somali pirates seized a yacht carrying four Americans and killed them while U.S. naval forces tried to negotiate their release.

Somali pirates have hijacked dozens of ships during the past few years, and taken in hundreds of millions of dollars in ransom money. The EU task force says the pirates are currently holding more than 30 ships and nearly 700 hostages.