Nairobi, Kenya ? The violent attack on a cruise liner off Somalia’s coast shows pirates from the anarchic country on the Horn of Africa are becoming bolder and more ambitious in their efforts to hijack ships for ransom and loot, a maritime official warned Sunday.

Judging by the location of Saturday’s attack, the pirates likely were from the same group that hijacked a U.N.-chartered aid ship in June and held its crew and food cargo hostage for 100 days, said Andrew Mwangura, head of the Kenyan chapter of the Seafarers Assistance Program.