At least 30 people have died as a wave of bombings struck Baghdad and northern Iraq.
The violence stoked fears that insurgents were trying to undermine confidence in the Shiite-led government amid rising sectarian tensions.
Extremists launched 12 attacks in the Iraqi capital and in the cities of Kirkuk, Samarra, Baqouba, Dibis and Taji. Mortars were fired into the northern cities of Beiji and Saddam Hussein's hometown of Tikrit, but no injuries were reported there.
Nearly 100 people were wounded in the rapid-fire explosions that unfolded over an hour and 15 minutes.
Half of the bombs struck at security forces and government officials - two frequent targets for insurgents still seeking to undermine Iraq's efforts to normalise after years of war and violence.
There was no immediate claim of responsibility for the attacks, but a military command spokesman said they resembled those carried out by al-Qaida.
The strikes marked the first major attacks in Iraq in nearly a month, although ongoing political battles between the Shiite-led government and top Sunni and Kurdish officials have threatened to inflame simmering sectarian disputes.
Iraq's Sunni Vice President, Tariq al-Hashemi, is wanted on terror charges that he says are politically motivated, and Kurdish regional leader Massoud Barzani has compared the government in Baghdad to a dictatorship. Aides to Prime Minister Nouri al-Maliki, a Shiite, have dismissed the criticism as baseless.
The single deadliest bombing came in Dibis, near the northern city of Kirkuk, 180 miles (290 kms) north of Baghdad. Six died when a parked car exploded in the Sunni Arab village.
Eight died in roadside bombings and car explosions across Baghdad mostly in Shiite neighbourhoods.