Karim Kadim, Associated Press
Followers of Shiite cleric Muqtada al-Sadr attend open-air Friday prayers in the Shiite stronghold of Sadr City, Baghdad, Iraq, Friday, Jan. 30, 2015.

BAGHDAD — An international rights group said Shiite militias allied with Iraqi security forces have escalated a campaign of abuse against Sunni residents in recent months, as gunmen assassinated a prominent Sunni tribal leader during an ambush in a Shiite district in Baghdad.

New York-based Human Rights Watch said in a statement that the militiamen, who are part of the fight against the Islamic State group, have begun driving Sunni families from their homes, kidnapping or summarily executing them in some cases.

The report said the abuses are taking place mainly in areas that were seized from the Islamic State group — which holds about a third of Iraq and Syria.

The militias — mainly volunteers who answered the call-to-arms from Shiite clerics — are growing more brutal, stoked by a desire for revenge against the Sunni extremists who have frequently butchered and attacked Shiites.

"Iraqi civilians are being hammered by ISIS and then by pro-government militias in areas they seize from ISIS," said Joe Stork, deputy Middle East and North Africa director at Human Rights Watch, using an alternative acronym for the Islamic State group. "With the government responding to those they deem terrorists with arbitrary arrests and executions, residents have nowhere to turn for protection."

Meanwhile, police said Sunday that Qassim Sweidan al-Janabi, as well as his son and six bodyguards, were killed when their motorcade was attacked by gunmen in Baghdad's northern Shiite district of Shaab. The attack, which took place late Friday, could fuel the ongoing sectarian tensions in the country.

A group of prominent Sunni politicians met to discuss the attack and urged the government to issue a law that would incriminate the Shiite militias, said Sunni parliament speaker Salim al-Joubori in a statement issued on Sunday.

Iraqi Prime Minister Haidar al-Abadi, a Shiite, said that the perpetrators are aiming to "distract the security forces in the confrontation against the real enemy...that is Daesh and to create a rift in the political process." Daesh is the IS group's Arabic acronym.

Meanwhile, Saad Maan, spokesman for Iraq's Ministry of Interior, told the Associated Press in a telephone interview that Iraqi security forces have arrested two relatives of IS group leader Abu Bakr al-Baghdadi.

Maan said al-Baghdadi's uncle Saleh Ibrahim and his niece's husband, Diaa Nouri Saadoun, were taken into custody in the Iraqi city of Samarra late Friday. He said both were found to have connections to the Sunni militant group and had intended to fight in Samarra, a Shiite holy city.


Associated Press writers Vivian Salama in Kirkuk and Murtada Faraj in Baghdad contributed to this report.