A leading figure in a US-allied Sunni militia has been killed by a roadside bomb in Taji, north of Baghdad, Iraqi police say.

Abed al-Khairiya was a senior member of the militia, or Awakening Council, in the town.

It is not clear who was behind the attack, which happened on Saturday.

The Sunni Arab Awakening Councils, which are sponsored by the US military, are opposed by Sunni insurgent groups, including al-Qaeda in Iraq.

There is also tension with the Shia-dominated special police.

If the Sunni-Shia divide is ever going to be reconciled the Sunnis must be willing to participate in the greater Iraqi government.  Al-Khairiya's was one such Sunni.  He was willing to support the US military against other Sunni insurgents.  His death is a blow to overcoming Iraq's sectarian problem.  That problem has always existed since the US invasion, and when it is full swing US casualties go up extremely fast.  This event is another in the last month and a half which demonstrates the seeming progress gained in Iraq over the last year is very fragile.  Shia on Sunni violence or vice versa would spark a wider conflict, one that would resemble the situation from a couple of years ago.  In a word- a bloodbath.