Three accused Somali pirates have pleaded not guilty to charges they killed four Americans in February after hijacking their yacht off the coast of Africa.

The men entered their pleas Wednesday in a U.S. federal court in Virginia. They denied all 26 counts related to the murder and kidnapping of the Americans. Most of the charges could bring the death penalty.

The owners of the yacht, Jean and Scott Adam, were shot to death along with their friends, Bob Riggle and Phyllis Macay, days after they were taken hostage south of Oman in the Arabian Sea.

U.S. Navy officials had been trying to negotiate their release when the shootings occurred.

They were the first Americans killed in the wave of pirate attacks and hijackings that have plagued the region in recent years.

The defendants are among 14 men charged in connection with the case. The other 11 defendants have already pleaded guilty to participating in the pirate attack, but not to the shootings.