German prosecutors on Wednesday issued arrest warrants for 13 suspected Central Intelligence Agency agents in connection with the alleged kidnapping of a German citizen in a forced renditions case that diplomats said could further strain relations between Washington and Berlin.

Christian Schmidt­Sommerfeld, the Munich prosecutor, said the unnamed people were wanted on suspicion of false imprisonment and causing serious bodily harm in the case of Khaled al-Masri, a Lebanese-born German detained in December 2003 in Macedonia and allegedly held until May 2004 by the CIA in a secret prison in Afghanistan.