It is unclear (as of late August 2003) who was behind the massive bomb attack that killed him. A spokesman for SCIRI in London suggested that supporters of Saddam Hussein may have been behind the attack; others suggest it may have been orchestrated by Sunnis not necessarily connected to Hussein who are opposed to the increasing Shia influence in the country; a few suggest it may have been carried out by hard-line Shia groups critical of Al-Hakim's increasingly conciliatory line towards the United States. However, as his assassination comes in the midst of a pattern of violence against Shia clerics in Najaf in recent weeks (Al-Hakim is the fourth to be assassinated), it is considered likely that the attack was motivated by anti-Shia sentiment rather than by a conflict between Shia moderates and hardliners.