A Spanish judge has summoned three Iraqi officers over a raid by Iraqi security forces on a camp housing an Iranian exile group.
The UN says 34 people were killed in the raid at Camp Ashraf, in Diyala province, in April 2011.
Judge Fernando Andreu has summoned Gen Ali Ghaidan Majid, the head of army, and two other officers to appear.
He is investigating allegations that crimes against humanity were committed during the raid on the camp.
The investigation is an enlargement of an existing probe on a separate raid which took place at the camp in July 2009, in which 11 people were killed.
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