Al-Qaida has apologised after an Islamic militant killed at least seven members of staff in a hospital in Yemen.

Qassim al-Rimi, leader of the jihadist group in the Arabian Peninsula, said that the Islamic fighter disobeyed orders when he entered the hospital attached to the Defence Ministry, during a December assault that killed 52 people.

According to Al-Rimi, the fighters were warned in advance not to attack the hospital, or enter the complex which contained it.

"We did not target them on purpose, this is not of our religion or our morals, we accept full responsibility for what happened in the hospital" Al-Rimi said in a video released by al-Qaida's media arm al-Mallahem.

"We rid ourselves of what our brother did. We did not order him to do so and we are not pleased with what he did. Now we acknowledge our mistake and guilt. We offer our apology and condolences to the victims' families. [..] We will pay blood money for the victims' families."

The unusual apology came after CCTV footage emerged of the Al-Qaida fighter shooting the unarmed hospital staff.

In one scene, the man can be seen cornering a group inside the compound's hospital building before throwing a grenade directly at them.

Al-Rimi explained that the Defence Ministry was attacked because it housed drone control rooms. He then added "we are continuing with our jihad" and warned that al-Qaida will attack any other military camps that "cooperate with the American drones by spying, planting chips, providing information or offering intelligence advice."

The authenticity of the English-subtitled video could not be absolutely confirmed, though it was consistent with other Associated Press reporting and came from al-Qaida's media arm.

The insubordinate fighter and eight other militants were killed in the 5 December suicide attack on the ministry complex in Sanaa, Yemen's capital. Seven foreigners from Germany, India, the Philippines and Vietnam were among the dead - all of them were providing aid to the hospital.