DUBAI, Feb 23 (Reuters) - A body set up by the Saudi-led coalition to investigate civilian casualties in Yemen said on Thursday a technical fault was responsible for the death of seven people in a 2015 air strike but cleared the alliance of other attacks.

Saudi Arabia and its allies in a mostly Gulf Arab military coalition have been bombing the Iran-aligned Houthi movement since they seized much of northern Yemen in 2015. The coalition has been repeatedly criticised over civilian casualties.

The Houthis have in turn regularly fired rockets towards Saudi cities and villages over the past two years. They say their attacks are in response to Saudi strikes on Yemeni cities and villages. The war has killed more than 10,000 people.

The Joint Incidents Assessment Team (JIAT), set up last year to investigate the coalition attacks, said in a statement that investigations into several of the incidents in 2015 raised by international rights groups, including United Nations bodies, had concluded that in most cases the coalition acted properly.

Speaking in the Saudi capital Riyadh, Mansour Ahmed al-Mansour, a legal JIAT adviser, told journalists that the investigation into a May 12, 2015, attack on a prison in the northern Hajjah province established that the coalition had targeted two arms depots located some 900 metres and 1,300 metres from the facility.

"The two targets belong to the armed Houthi militias, and thus both are within the legitimate military targets ... and that the prison building was not targeted or affected by the coalition air strikes," the statement said, according to Saudi state news agency SPA.

Investigators also cleared the coalition from responsibility for two other attacks raised by U.N. experts and the U.N. High Commision for Human Rights in the northern town of Haradh near the Saudi border; one on a hospital on July 7, 2015 and another on a camp for displaced people on March 30, 2015, the statement said.

It said that in both cases Houthi fighters and an arms depot were targeted by the coalition.

The statement did not address if there were casualties at the hospital and the camp or who caused them.

But an investigation into the death of seven people in a May 2, 2015, attack on a market in the city of Saada in northern Yemen found that a technical fault in an aircraft on a mission to target a Houthi arms depot had caused a bomb to fall some 60 metres away from an arms depot it had intended to target, the report said. It hit and damaged a building, the report said.

"In light of what had been mentioned, the JIAT concluded that the incident happened due to a purely technical fault in the plane, and thus the team (JIAT) sees that the coalition forces must apologise for the damages that happened due to the technical fault ... and to provide the necessary aid to the families of those affected," it said.

(Reporting by Sami Aboudi; Editing by Alison Williams) ((Sami.Aboudi@thomsonreuters.com; +97143918301;))