A fuel truck blew up near a gas station in western Baghdad where drivers were lining up for fuel, killing at least 50 people and injuring 60.
The blast occurred in the mainly Sunni neighborhood of Al-Mansur. Police say the bombing may have been the work of a suicide bomber.
Earlier, a car bomb killed 15 civilians and wounded at least 30 in the busy Al-Hurriyah square in central Baghdad's mixed Al-Karradah district.
News reports quoting figures compiled by Iraqi authorities say that more than 1,600 civilians were killed nationwide in July -- one-third more than in June.
Meanwhile, U.S. Vice President Dick Cheney has said he expects a pivotal September report on the war in Iraq to show "significant progress."
Cheney made the statement on July 31 in an interview with CNN news television.
General David Petraeus, the U.S. commander in Iraq, and Ryan Crocker, the U.S. ambassador to Iraq, are required to report to Congress by September 15 about progress in Iraq.
Their evaluation is expected to influence decisions on how many U.S. troops will stay in Iraq, and for how long.
(compiled from agency reports)