Diplomatic sources say that pirates have seized a South Korean cargo ship off the coast of Somalia.

The sources say the ship was carrying at least eight South Korean crew members and a number of foreigners when pirates seized it Wednesday.

Somali pirates have attacked dozens of ships this year and are now believed to be holding 11 ships and their crews hostage.  Somali officials say the large ransoms being paid by ship owners are fueling the piracy.

The Somali government, fighting an Islamist insurgency, lacks the resources or power to stop the pirates.

The International Maritime Bureau advises ships traveling near Somalia to keep more than 200 nautical miles offshore and report any boats that look suspicious. 

Some information for this report was provided by AFP, AP.