When Ruknuddin had left Iran for Karakorum, there had taken place a wild massacre of the Iranian Ismailis, who were in Mongol's custody. His family and dependents detained at Qazwin were also put to the sword by Qaraqai Bitikchi. Another cruel Mongol commander, called Otegu summoned the Ismailis of Kohistan to throng at one place, and butchered some 12,000 of them. W. Montgomery Watt however writes in his "Islamic Philosophy and Theology" (Edinburgh, 1985, pp. 153-4) that, "The fall of Alamut to the Mongols in 1256 was followed by massacres, but many Ismailites survived and the son of the last Imam was preserved safely in hiding." When Halagu had finished his merciless operations, he decided to kill Ruknuddin out of Iran, through his envoy Bujrai.