Four suicide bombings targeting Iraqi security forces and civilians and mortar fire that struck houses near Baghdad killed at least 17 people on Monday, security and medical officials said.
The morning attacks also wounded at least 64 people, the sources said.
In the deadliest single attack, a suicide bomber struck a street in the southern port city of Basra, killing five people and wounding 10.
The Islamic State group, "after the losses it suffered in western areas, is seeking to move the battle to the southern areas," where many of the forces fighting the jihadists are from, Basra Governor Majid al-Nasrawi told journalists.
IS overran large areas north and west of Baghdad in 2014, but Iraqi forces backed by US-led air strikes and training have since regained significant ground, most recently in the western province of Anbar.
AFP journalists saw three burned bodies at the scene of the Basra attack -- two still inside vehicles, and a third on a stretcher.
The blast set vehicles alight and damaged buildings in the area, one of the journalists said.
Another bomber struck a joint police and army checkpoint in north Baghdad, while a third attacked pro-government paramilitaries in Mishahada, north of the capital, and a fourth hit militiamen in a restaurant south of the city of Nasiriyah.
And mortar fire struck houses in Abu Ghraib, west of Baghdad, killing two people and wounding at least seven, officials said.
There was no immediate claim of responsibility for the attacks, but the Islamic State group frequently carries out suicide bombings in Iraq targeting civilians and security forces.
Like the Basra governor, a US army officer said that as IS loses territory, it is increasingly turning to bombings in a bid to stay relevant.
The group is "losing its prominence on the battlefield, and so what we've kinda seen recently is a lot more what we call high profile attacks," Captain Chance McCraw told journalists in Baghdad.
The jihadists are seeking "to still stay relevant in the media, because that's how they get their message out," McCraw said.
A suicide bomber blew himself up following a football tournament south of Baghdad last month, killing more than 30 people. More than 45 people died in a suicide truck bombing at a checkpoint earlier in March.