Ahmed al-Darbi of Saudi Arabia entered the plea during an arraignment Thursday before a U.S. military tribunal judge. He is charged with terrorism, attacking civilians and hazarding a vessel for alleged complicity in the al-Qaida attack on the French-flagged MV Limburg.

Al-Darbi is a relative by marriage to one of the Sept. 11 hijackers who crashed a plane into the Pentagon. He’s been at the prison in Guantanamo Bay, Cuba, since 2002.

The arraignment was in Cuba but viewed by some journalists via closed circuit at Fort Meade military base near Baltimore.