A series of car bombs near Shia places of worship has killed at least 20 people and injured many, a day after multiple blasts had hit two Iraqi cities killing nine people, a year after US forces departed the country.
Three gunmen attacked a police checkpoint on the highway west of Tikrit, killing one policeman and wounding three.
A police patrol then chased the gunmen, who abandoned their car and then detonated explosives in it, killing four more police and wounding two, a police lieutenant colonel told the AFP news agency.
In the village of Al-Buslaibi, north of Baghdad, a roadside bomb targeting an army patrol killed three soldiers, an army captain said.
A car bomb exploed in Khaznah, a village near Mosul in north Iraq populated by the small Shabak minority, killed seven people and wounded 12, while two car bombs near a Shia place of worship killed five and wounded 20 in
the northern flashpoint town of Tuz Khurmatu, police officers and doctors said.
Monday's violence comes a day after a string of bombings and a shooting which killed 19 people.
Two car bombs and seven roadside bombs on Sunday targeted two Shia places of worship in Kirkuk, one in the city's north and another in its south, killing a total of five people and wounding 14, a senior police officer told the AFP news agency.
The attacks occurred around 7:30pm local time (16:30GMT), the officer said. A doctor from Kirkuk general hospital confirmed the toll.
Earlier on Sunday, a car bomb explosion near a Kurdish party office killed two Kurdish security recruits and wounded five in a disputed city north of the capital, Baghdad.
Security officials said the blast targeted the Patriotic Union of Kurdistan (PUK) office in Jalawla some 125km northeast of the capital.
An officer in the Jalawla police said the bomb exploded at the local headquarters of Iraqi President Jalal Talabani's Patriotic Union of Kurdistan after a number of people seeking to join the Kurdish Peshmerga security forces had gathered.
Both Arabs and Kurds claim Jalawla, and a local policeman said the violence resulted from the tensions. He did not explain further.
Ethnically mixed Jalawla is in Diyalah province, and is one of the areas which Iraq's autonomous Kurdistan region wants to incorporate, over the strong objections of Baghdad.
The dispute over territory in northern Iraq is the greatest threat to the country's long-term stability, diplomats and officials say.