Piracy attacks increased in 2010 for the fourth year, according to an annual report by the International Maritime Bureau (IMB).
Pirates attacked 445 ships, took 1,181 people hostage and killed eight during the year.
The number of attacks increased 10% compared with 2009.
According to the IMB, hijackings off the coast of Somalia accounted for 92% of all ship seizures last year, with 49 vessels hijacked and 1,016 crew members taken hostage.
The report says 28 vessels and 638 hostages were still being held for ransom by Somali pirates as of 31 December 2010.
While attacks off the coast of Somalia rise, the number of attacks in the Gulf of Aden more than halved last year, with 53 attacks in 2010 compared with 117 in 2009.