Two Somali pirates are expected to be sentenced to life in prison Friday for their roles in a hijacking that led to the death of four Americans.

Said Fooley and Abdi Aqid will appear in U.S. District Court in the eastern city of Norfolk, where two other Somalis involved in the attack received life sentences on Thursday.

Those pirates — 32-year-old Mohamud Issa Ali and 20-year-old Jilani Abdiali, had pleaded guilty to piracy charges related to their involvement in the hijacking.

Issa Ali admitted to commanding the pirate ship that seized the Americans' yacht, the Quest, off the coast of Oman in February.

The Americans — Jean and Scott Adams of Marina del Rey, California and their friends Bob Riggle and Phyllis Macay of Seattle — were taken hostage, and shot to death a few days later as U.S. Navy forces tried to negotiate their release.

Under U.S. law, piracy carries a mandatory life sentence.

Three other Somalis accused of being the shooters face trial on piracy and murder charges next year. Those charges could carry the death penalty.

Somali pirates have made hundreds of millions of dollars hijacking ships for ransom in recent years.

The Adamses, Riggle and Macay were the first Americans to die in a recent pirate hijacking.