A senior leader of al-Qaeda in Yemen has been killed by a US air strike, according to a statement distributed by the group online.

The group said in a statement on Tuesday that Ibrahim al-Rubaish, a Saudi, was killed in a drone attack two days earlier. The group did not specify where the purported strike took place.

Al-Rubaish had a $5m bounty on his head.

The death of al-Rubaish may be a sign that a covert US drone programme against Yemen's branch of the armed group continues despite the evacuation of American military advisers from the country amid a worsening civil war.

Yemeni and US officials had no immediate comment on the claim.

The group said al-Rubaish, who is from Saudi's ultra-conservative Qassim region, "has spent two decades of his life in jihad, fighting America and its agents".

He first fought in Afghanistan before he was arrested and held in the US military prison of Guantanamo for "a few years" before he joined al-Qaeda.

Al Jazeera's Hashem Ahelbarra, who has reported extensively on Yemen, said al-Rubaish was "someone who has huge influence" among Yemen's al-Qaeda fighters.

"He was very charismatic," our correspondent said. "He was someone very instrumental in the surge of recruitment of fighters in Yemen."

Al-Rubaish reportedly urged Yemenis to fight in Syria, and recently called for the killing of Houthi leaders and former Yemeni leader Ali Abdullah Saleh, he added.

Breakdown of Yemen security

Al-Qaeda in the Arabian Peninsula (AQAP) was formed in 2009 after a merger between fighters in Yemen and Saudi Arabia.

Al-Qaeda fighters have exploited the breakdown of security as a Saudi-led coalition last month launched an air campaign against Houthi rebels amid fierce fighting between rival Yemen forces.

Among its gains, al-Qaeda has seized Mukalla, the capital of Hadramawt province.

US Defence Secretary Ashton Carter acknowledged last week that al-Qaeda was making gains and that the fighting in Yemen was complicating counterterrorism efforts, but vowed that they would continue.

In an audio message in January, al-Rubaish urged attacks on the West, singling out France.

He also called on Muslims to target, "without consulting anyone", those who mock the Prophet Muhammad.

Al-Rubaish's message followed the deadly January 7 attack on satirical French magazine Charlie Hebdo, which was claimed by al-Qaeda.

The al-Qaeda group in Yemen and Saudi Arabia has a track record of launching attacks far from its base in Yemen, including an attempt to blow up an American airliner over Michigan on Christmas Day in 2009.

Al-Rubaish was considered the group's main ideologue and theological adviser and his writings and sermons were prominent in its publications.

Last year, he hailed the seizure of swaths of land in Iraq and Syria by al-Qaeda's rival, the Islamic State of Iraq and the Levant group.