The bodies of 31 men were found dumped at eight sites, most of them in predominantly Shi'ite parts of Baghdad, police said Thursday.
The victims were all shot and most had their hands bound, police said.
Late Wednesday, 14 bodies were found in the Shi'ite slum of Sadr City, Police Lt. Muhammad Khyoun said. Five more bodies were found in and around the neighborhood that night, including two in a square and two near a school, Khyoun and police Lt. Ahmed Qassim said.
Two more bodies were found in the northern Ur neighborhood and two along the main road of southeastern Zafaraniyah area, Police Lt. Thaer Mahmoud said.
Early Thursday, gunmen in three cars raided a house in Dora, a predominantly Sunni Arab neighborhood of Baghdad, seizing seven men from one family, Police Lt. Maitham Abdul Razzaq said.
Their bodies were found three hours later scattered along the main road. All had their hands bound and bullet shots to the head, Razzaq said.
Another body was brought to the Kut morgue Thursday morning, according to Hadi al-Atabi, an official there. The victim was found cuffed and blindfolded in Aziziyah, 55 kilometers (35 miles) southeast of Baghdad, he said.
The grisly finds come amid reprisal attacks for the bombing Wednesday of a revered Shi'ite shrine in Samarra. It was not immediately clear whether the killings were linked to that attack.