A leader of an alliance of Sunni Arab tribes which opposes al-Qaeda in Iraq has been killed in a double suicide bomb attack in Falluja, police say.
The tribes' alliance with US and Iraqi forces has reduced violence
Sheikh Ibrahim Mutayri al-Mohammedi, a senior member of the Awakening Council in the city, was killed along with one of his aides at his home on Saturday.
Police said the five men who carried out the attack belonged to al-Qaeda in Iraq and were killed in the explosion.
Several leaders of Awakening Councils have been killed in the past year.
The head of the alliance in the province, Sheikh Abdul Sattar Abu Risha, a key US ally who was widely credited with having defeated al-Qaeda in much of western Iraq, was assassinated in September.
The Sunni tribes' alliance with US and Iraqi forces has been a key factor in helping reduce dramatically the violence in and around Baghdad, and has forced many al-Qaeda in Iraq fighters to flee to other provinces.
Sheikh Mohammedi was killed when five members of al-Qaeda in Iraq attacked his home in al-Saqlawiya, a northern district of Falluja, on Saturday, police said.
The Iraqi satellite channel, al-Sharqiya, reported that the two suicide bombers among the group had been brothers.
An adviser to the Awakening Council, Thamir al-Tamimi, said groups allied to al-Qaeda in Iraq had recently been targeting its leaders to "settle scores".
In other violence on Saturday, the leader of the journalists' union in Iraq, Shihab al-Tamimi, was shot and seriously wounded by unidentified gunmen in Baghdad.
Mr Tamimi, who is in his 70s, has been the head of the union for several years.
The international media watchdog, Reporters Without Borders, said recently that nearly 50 journalists were killed in Iraq last year.