The Pentagon has mistakenly released 10-year-old footage it claimed had been seized during a recent anti-terror offensive in Yemen.

The US military said the video clips were seized during the 29 January raid in Yemen that killed terrorists, but also left a Navy SEAL dead and reportedly resulted in civilian fatalities.

However, it has since emerged the clips of jihadist training footage, which included bomb-making instructions, were captured during a 2007 raid. The footage has been removed from the military's video distribution site.

Initially, US Central Command had said in a statement seen by The Hill the video was "one example of the volumes of sensitive al-Qa'eda terror-planning information recovered during the operation."

However, Pentagon spokesman Navy Capt. Jeff Davis, while acknowledging the videos were a decade old, said they had been found during the Yemen raid.

"It does not matter when the video was made," Davis said in comments carried by Politico. "That they had it is still illustrative of who they are and what their intention was."

Although the Pentagon claimed the raid in al-Bayda province killed 14 members of the militant group al-Qaeda in Arabian Peninsula (AQAP), medics on the scene said that at least 30 people died, of which 10 were women and children.

Local sources said that an 8-year-old American girl named Nawar al-Awlaki was also killed in the attack. She is the daughter of a senior al-Qaeda cleric and US citizen Anwar al-Awlaki, who was killed in 2011 in a drone strike.

Meanwhile, three military officials told Reuters that the attacking SEAL team faced hostile conditions as President Trump approved his first covert counter terrorism operation without enough intelligence, back up preparation and ground support.