Another bloody day in Baghdad has left at least 45 people dead, after six bombs exploded minutes apart in mainly Shiite district in the southwest of the city on Sunday.
And north of the capital, two British helicopters went down after an apparent in-air collision, killing two British crew members.
One day earlier, dozens of people were killed in sectarian violence in Karbala when a bomb exploded at a bus station close to one of the holiest Shiite shrines in the country.
U.S. military officials said an investigation will be carried out into what caused the deadly helicopter crash 15 kilometres north of Baghdad. In addition to those killed, four others were injured.
Initial reports have suggested the crash was an accident, and not the result of enemy fire.
"Sadly, two personnel have died and one is very seriously injured. All of these were U.K. personnel. My thoughts and sympathy are with them and their families," U.K. Defense Secretary Des Browne said, adding that the next of kin had been informed.
Initial U.S. reports suggested the helicopters -- which went down in an area where the Brits rarely fly -- belonged to the "coalition," but the comments were later revised.
"I can't talk about the particular mission they were involved in, but we do have units operating as part of the coalition across Iraq," a British defense ministry official said on condition of anonymity, in line with government policy.
In addition to two bombs in a Baghdad market on Sunday, a suicide bomber detonated his explosive on a minibus in the northwest part of the city, killing at least eight people and wounding 11, The Associated Press reports.
The attack took place near the al-Sarafiyah bridge, which was knocked down by a suicide truck bomb attack earlier this week that killed 11.
The Jadriyah bridge was also targeted on Saturday by a bomber. Ten people were killed in that strike, though the span was not damaged.
Meanwhile, Iraq's legislature descended into chaotic arguing Saturday as elected officials fought over who was to blame for lax security that permitted a suicide bomber to get inside parliament on Thursday and kill a Sunni Arab lawmaker.
The ongoing violence comes despite a U.S. crackdown on the capital in an attempt to bring peace and allow the fledgling government to function.
With files from The Associated Press
