Car bombs and roadside blasts killed at least 22 people in Shi’ite districts across the Iraqi capital Baghdad on Tuesday, police and hospital sources said.
Nearly 100 people were injured, police sources told the BBC.
The attacks came on the 10th anniversary of the US-led campaign in Iraq that toppled Saddam Hussein.
Violence has decreased sharply from its peak, but a low-level Sunni insurgency continues, with an average of more than 300 people killed each month.
On Monday, car bombers and roadside blasts struck across Baghdad, while a suicide bomber in a truck attacked a police base in a Shia-dominated town just south of the capital, police and hospital sources told Reuters news agency.
One report quoted police as saying the attacks had targeted street restaurants, daily labourers and bus stops, and spanned a period of about one hour.
No-one has said they carried out the attacks, though the Iraqi branch of al-Qaeda, Islamic State of Iraq, has launched a number of high-profile attacks this year.
Sunni Islamist insurgents tied to al Qaeda have stepped up their campaign of attacks this year in an attempt to trigger sectarian tensions and undermine Prime Minister Nuri al-Maliki’s Shi’ite-led government.