The Islamic State group’s branch in Afghanistan vowed revenge Tuesday for a drone strike that killed its deputy leader. Mullah Abdul Rauf Khadim was a former Guantanamo Bay detainee, also known as Abdul Rauf Aliza, and was killed in a NATO drone strike Feb. 9.  

Hafiz Saeed Khan, governor of the group also known as ISIS’s Khorasan Province, confirmed Khadim’s death in a video released through the group’s media office.

Khadim's death was just the first of two serious blows to the group's leadership in Afghanistan. Afghanistan Security Forces confirmed Monday an operation in Afghanistan’s Helmand province killed deputy leader Hafiz Wahidi. Wahidi was not mentioned in the video.

Hafiz Wahidi was appointed as deputy little more than a month ago to replace Khadim, who was believed to be his uncle, according to a statement from Afghanistan Ministry of Defense confirming his death. Nine others were killed in Monday’s operation but their identities are not known.

Khadim was sent to Guantanamo Bay in 2004, accused of being a high-ranking member of the Afghan Taliban. He was released to Afghanistan in 2007, and was reportedly welcomed back into the group's Pakistani branch. He then defected to ISIS and was appointed deputy leader of the group’s Khorasan branch.

ISIS announced Khorasan Province in January, appointing 12 emirs in both Pakistan and Afghanistan. At least five of its leaders were former members of Tehreek e-Taliban e-Pakistan, the Pakistani branch of the Taliban, who defected from the group in October after pledging allegiance to ISIS caliph Abu Bakr al-Baghdadi.