At least 75 people were killed and 250 injured in around 20 bombings and attacks across Iraq on Monday, one of the bloodiest days of the year and just after the start of the Islamic holy month of Ramadan, dpa reported.
In the capital Baghdad, 32 people were killed and 88 injured in car bomb blasts and other explosions, Al Sumaria news website reported.
The bombings took place in the Shiite-dominated al-Sadr City, al-Taji and al-Hussainiya areas in Baghdad.
A shelling attack on army barracks near the city of Tikrit killed at least 15 soldiers and injured four others, police officials told dpa.
"Gunmen fired shells at the army's barracks in al-Doloiya area, followed by clashes between them and troops," sources said.
Al-Doloiya area is located near Tikrit, some 80 kilometres north of Baghdad. Two other people were killed in separate blasts in Tikrit.
Car bombs also hit the central Baquba city, the southern city of al-Diwaniya and the northern city of Kirkuk, killing an unknown number of people.
In the northern city of Mosul, six security personnel and two civilians were killed in attacks, which targeted a busy market in the city and an army patrol. Shoot-outs also took place between gunmen and police forces.
Monday's attacks follow a series of bombings that shook Iraq on Sunday evening, killing more than 12 people.
Violence in Iraq has dropped dramatically in recent years, but near-daily attacks still take place amid a political stalemate in the country stemming from feuds between Shiite and Sunni politicians.
Insurgents usually escalate their attacks during Ramadan. Last year, al-Qaeda launched 100 attacks during the holy month to avenge the death of its former leader Osama bin Laden, during which dozens were killed.