Abdallah Ali al-Ajmi was transferred back to his home country of Kuwait after his release from Guantanamo in 2005. Last April he blew himself up in a homicide attack that killed 12 people in Mosul, Iraq.

Al-Ajmi, known in Guantanamo as Detainee 220, made his martyrdom tape before the attack.

"In the name of Allah, most compassionate, most merciful and prayers and peace be upon our Prophet," al-Ajmi says in the video. "I thank Allah, Lord of the Worlds, who freed me from Guantanamo prison and, after we were tortured, connected me with the Islamic State of Iraq [ISI]. And it is the gift of Allah to follow the path of this nation, the ISI."

In the video, translated by the NEFA Foundation, a non-profit that tracks terror groups, al-Ajmi mentions Guantanamo Bay right away. For many jihadists, having served time at Guantanamo is seen as a badge of honor.

Al-Ajmi's attack is one of the most well known and well documented cases of an ex-Gitmo detainee returning to the battlefield as a homicide bomber. His video renews concerns of many in the intelligence community of the potential consequences by releasing these prisoners.

Sixty-two detainees released from the U.S. Navy base prison in Cuba are believed to have rejoined the fight, said Pentagon spokesman Geoff Morrell, citing data from December. That's up from 37 as of March 2008, Morrell said.

The new figures come as President-elect Barack Obama issued an executive order last week to close the controversial prison. It's unlikely, however, that the Guantanamo detention facility will be closed anytime soon as Obama weighs what to do with the estimated 250 Al Qaeda, Taliban or other foreign fighter suspects still there.

FOX News' Catherine Herridge and the Associated Press contributed to this report.