At least 36 members of the Sahwa militia were killed Sunday in a suicide bomb explosion believed to have been carried out by a pair of attackers with Down Syndrome, security sources told DPA.
If confirmed, that would mark a new low in Iraq's recent bloody history. Security sources said the two bombers set off their own explosive belts.
The attack - which left a further 28 people injured - took place in the Sunni-dominated area of al-Radwaniya in southwestern Baghdad, where Sahwa members were gathered to collect their salaries.
The leader of Sahwa in al-Radwaniya, al-Haj Abd, and four of his brothers are among those killed, the security sources told DPA.
Separately, in Baghdad's Abu Ghreib area, one Sahwa leader, Amer al-Tamimi was killed when a bomb attached to his car went off.
Al-Tamimi is the brother of the government advisor to the Awakening Councils Abu Azzam Al-Tamimi.
In Anbar province, four Sahwa fighters were killed, including Sahwa leader in the area Khelief Ahmed, were killed in a suicide bombing.
Six people were injured in the attack on meeting for Sahwa in al-Qaem area, some 500 km west of Baghdad, police said.
The Sahwa tribal security forces, or Awakening Councils, are made up of former Sunni insurgents who have been supporting the government in its fight against Al Qaeda and helping restore order in the country.
Mohammad al-Anbari, leader of Sahwa fighters in Abu Ghreib, told DPA that the attacks are to 'revenge from the tribal forces after they have helped in achieving security and stability in areas that were controlled by Al Qaeda'.
Although the level of sectarian violence in the aftermath of the 2003 US-led invasion has fallen sharply in the past two years, political tensions continue amid the unresolved problem of forming a new government after the March parliamentary elections.