SANAA, Yemen, April 14 (UPI) -- Al-Qaida in the Arabian Peninsula announced its top cleric, Ibrahim al-Rubaysh, upon whom the United States placed a $5 million bounty, died in an attack in Yemen.

The group posted a statement online saying al-Rubaysh died over the weekend in a "crusader attack."


It's unclear exactly who carried out the attack and where it took place.

A Saudi-led coalition of Arab nations last month began airstrikes on Yemen against Houthi rebels, but AQAP is also present in the area.

Al-Rubaysh was detained at Guantanamo Bay prison from 2002 to 2006. He is described by the U.S. State Department's Rewards for Justice website as a "senior AQAP sharia official since 2013."

As such, he "provides the justification for attacks conducted by the AQAP," the website says, adding that he is a senior advisor for AQAP operational planning.

U.S. officials did not immediately confirm reports of his death.