Police found the bodies of four men in an open field in Baladiyat, a mixed Sunni-Shiite neighborhood in east Baghdad. The victims had been handcuffed and hanged, police Capt. Mahir Hamad Moussa said, noting the rope marks on their necks.
Another body, shot in the head, was found near a shop in the eastern Kamaliyah suburb, which has also suffered repeated attacks.
A US military patrol found 18 bodies in an abandoned minibus in western Baghdad early Wednesday, Iraqi police said.
The victims had been handcuffed, blindfolded and hanged or shot, police Lt. Maitham Abdul-Razzaq said. At least two appeared to be foreign Arabs, he added.
The bus containing the bodies was found on the road between Amiriyah and Khadra, two of Baghdad's most dangerous neighborhoods, Abdul-Razzaq said.
The grisly finds follow a surge of sectarian violence unleashed by the February 22 bombing of a famed Shiite shrine in the central city of Samarra and reprisal attacks against Sunni mosques and clerics. While sectarian killing has diminished in recent days, other attacks have increased.