Saeed al-Shihri's death is a major breakthrough for US-backed efforts to cripple the terror group in the impoverished Arab nation.
Al-Shihri, a Saudi national who fought in Afghanistan and spent six years in the US military prison at Guantanamo Bay, was killed by a missile after leaving a house in the southern province of Hadramawt, according to Yemeni military officials. They said the missile was believed to have been fired by a US-operated, unmanned drone aircraft.
Two senior US officials confirmed al-Shihri's death but could not confirm any US involvement in the air strike. The US does not usually comment on such attacks although it has used drones in the past to go after al Qaida members in Yemen, which is considered a crucial battleground with the terror network.
Yemeni military officials said that a local forensics team had identified al-Shihri's body with the help of US forensics experts on the ground. On Monday night, after speculation surfaced that the attack was carried by a US drone, Yemen's Defence Ministry issued a statement saying al-Shihri and six companions were killed during an operation by Yemeni armed forces in Wadi Hadramawt, but it did not elaborate on how they were killed.
Yemeni military officials said they had believed the United States was behind the operation because its own army does not the capacity to carry out precise aerial attacks and because Yemeni intelligence gathering capabilities on al-Shihri's movements were limited.
Al-Shihri's death is a major blow to al Qaida's Yemen branch, which is seen as the world's most active, planning and carrying out attacks against targets on and outside US territory. US drone strikes have intensified in Yemen in recent months, killing several key al Qaida operatives, including Samir Khan, an al Qaida propagandist who was killed in a drone strike last year.
Meanwhile, the leader of al Qaida has confirmed the death of the group's second-in-command, who was killed in a US drone strike in north-western Pakistan in June. In a video posted on militant websites, al Qaida chief Ayman al-Zawahiri described his late lieutenant Abu Yahya al-Libi as a "lion of jihad and knowledge".
The killing of al-Libi, who was Libyan by birth, was the biggest setback to al Qaida since the death of Osama bin Laden.
Later, Yemeni officials said a car bomb targeting the motorcade of the country's defence minister killed at least 13 people, but the minister escaped unharmed. The security officials said the minister, Major General Mohammed Nasser Ahmed, was unhurt but that eight of his security guards were killed. The other five dead were civilian bystanders.