Seven pilgrims were killed in a spate of bombings with the deadliest attack involving two near-simultaneous blasts.
More Iranian pilgrims die in Iraq bombings
Seven Iranian pilgrims were among 10 people killed in a spate of bombings across Baghdad on Saturday morning, security officials said.
The deadliest attack involved two near-simultaneous blasts, one at a derelict house laced with explosives and the other a car bomb, close to a rest house popular with Iranian religious tourists in Kadhimiyah. Five pilgrims were killed and 18 wounded.
And in the Shuala neighbourhood, a suicide bomber driving a vehicle packed with explosives rammed into a bus carrying Iranian religious tourists before detonating his payload. Two Iranians were killed and 28 wounded.
The violence came a day after 14 Iranian pilgrims were killed in an accident when two buses collided in southern Iraq, and 42 others were injured. That was out of an overall toll of 17 dead and 53 wounded.
Every day, thousands of pilgrims, many of them from Iran and other countries with large Shiite Muslim populations, visit Najaf and Iraq's other major Shiite shrines in Samarra, Karbala and Baghdad.
Meanwhile, in the south Baghdad neighbourhood of Bayaa, two people were killed and 32 others wounded when a car bomb blew up, the interior ministry official said.
Another person was killed and eight wounded when a roadside bomb targeting civilians exploded near Oqba bin Nafia square in the capital's central commercial district of Karrada, defence and interior ministry officials said.
While violence has dropped dramatically across Iraq since its peak in 2006 and 2007, attacks remain common, especially in Baghdad and the restive northern city of Mosul.
The number of people killed in violence in Iraq last month was the lowest in a year for the second month running, with 171 people - 105 civilians, 23 soldiers and 43 policemen - dying in attacks.