NEW : The Pompei , a Belgian - built ship , was one of two vessels attacked . NEW : Islands where attack occurred are roughly 100 miles off Somali coast . The second ship escaped the attack after a brief exchange of gunfire with pirate vessels , the pirate source added . Dutch naval forces killed seven pirates and freed two captive fishermen . Pirates were disarmed and released because crew lacked strength to hold them .
NEW : The Pompei , a Belgian - built ship , was one of two vessels attacked . NEW : Islands where attack occurred are roughly 100 miles off Somali coast . Dutch naval forces killed seven pirates and freed two captive fishermen . Pirates were disarmed and released because crew lacked strength to hold them .