Complex sentence: Grigoryan was killed in Stepanakert, Nagorno-Karabakhhe KGB office had reported that he was killed by opponents of the Armenian-Azerbaijani truce.
Split into simpler sentences: Grigoryan was killed in Stepanakert, Nagorno-Karabakh. The KGB office had reported that he was killed by opponents of the Armenian-Azerbaijani truce.