People gather at the site of a blast where a suicide bomber blew up his explosives-laden ambulance in Iraq's holy city of Samarra, north of Baghdad, Iraq, November 6, 2016. (Reuters)
The Islamic State group has claimed responsibility for Sunday's attacks that killed at least 20 north of Baghdad.
The spokesman for Salahuddin province, Ali al-Hamdani, says the deadliest was in Samarra where a suicide bomber blew himself up among Shia pilgrims after detonating a parked car bomb, killing 11 and wounding up to 100.
Iranian pilgrims were among the casualties.
The city, 60 miles (95 kilometers) north of Baghdad, is home to a revered Shia shrine.
Al-Hamdani added that another suicide bomber rammed his explosives-laden car into a check point outside the Salahuddin provincial capital, Tikrit, killing at least nine people and wounding 25.
The Associated Press could not verify the authenticity of the IS claim, but it was posted on a militant website commonly used by the extremists.