(CNN) -- Fourteen suspected pirates appeared Thursday in federal court in Virginia, about 7,000 miles from where they were captured for their alleged role in the February hijacking of a yacht that led to the deaths of four Americans.
The men -- 13 Somalis and one Yemeni -- faced charges of piracy, kidnapping and use of a firearm in the commission of a crime in a Norfolk, Virginia, court.
"The indictment states that, without provocation, the pirates allegedly shot (at) a Navy ship ... and then executed four Americans," U.S. Attorney Neil McBride told reporters Thursday.
According to U.S. officials, the four Americans -- ship owners Jean and Scott Adam, along with Phyllis Macay and Bob Riggle -- were found shot after U.S. forces boarded their vessel. McBride said "at least three" of the alleged pirates indicted this week purposefully killed the four Americans.
McBride, the U.S. attorney for the eastern district of Virginia, noted that the piracy count carries a life sentence. While no murder charges have been levied against any of the alleged pirates, McBride said that more charges can be filed before the men's trials get underway.
A grand jury indicted the men Tuesday, but the indictment was sealed until the suspects appeared in court Thursday.
The victims' ship, Quest, was being shadowed by four U.S. warships after pirates seized it off the coast of Oman in February.
U.S. forces responded after a rocket-propelled grenade was fired at a U.S. Navy ship about 600 yards away -- and missed -- and the sound of gunfire could be heard on board, according to U.S. Navy Vice Adm. Mark Fox.
The men were found to be in possession of several assault rifles and a rocket-propelled grenade launcher, according to the indictment. They tossed additional weapons into the ocean as U.S. forces approached, it said.
It was the first time in recent history that Americans have been killed in a suspected pirate attack in the Gulf of Aden, Carr said.
CNN's Carol Cratty contributed to this report.