At least 17 people, most of them Shia Muslims have been killed in bombings across Iraq.
The deadliest of the attacks took place in Baghdad's mainly Shia district of Bayaa.
A car bomb blew up near a gathering of Shia pilgrims, killing seven people and injuring another 16.
Three people were killed and ten injured in a mainly Shia district on the south eastern outskirts of Baghdad when a roadside bomb exploded in a vegetable market.
In the district of Husseiniya, a bomb left inside a restaurant killed two people and injured another five.
No group immediately claimed responsibility for the attacks,which came a few days before Arbae'en, a holy ritual in which Shias commemorate the death of Imam Hussein, grandson of Prophet Mohammed.
Iraqi security services have been on high alert since last week as they expect more attacks targeting Shia communities in the coming days.
Shias are considered apostates by hard line Sunni Islamist insurgents who have been regaining momentum in Iraq this year.
Gunmen ambushed a military vehicle and shot dead three soldiers in western Tikrit, 150km north of Baghdad.
Two more soldiers were shot dead when gunmen opened fire at a checkpoint east of the Iraqi capital.
Iraqi authorities blame al-Qaeda for the rise in violence in the country, saying it is trying to destabilise the Shia-led government and foment inter communal conflict.
Insurgent attacks in Iraq have risen since the start of the year, with hundreds killed each month.
The growing violence has raised fears of a return to the heights of bloodshed seen in 2006-7, when tens of thousands died.
Iraq's sectarian balance has come under further pressure from the civil war in neighbouring Syria, where mainly Sunni rebels are fighting to topple a leader backed by Shi'ite Iran.
So far Shia militias, most of which disarmed in recent years and joined the reconstituted security forces or entered the political process, have largely held their fire.
But a worsening Sunni insurgency could prompt Shia militia to again take up arms.