A suicide bomber killed at least 25 people in Baghdad on Friday while seven died in other attacks, as security forces seek to stem spiralling violence with wide-ranging anti-insurgent operations.
Diplomats and analysts say the authorities are failing to tackle the root causes of months of heightened unrest, but Prime Minister Nuri al-Maliki has vowed to press on with a campaign against militants, which is among the biggest of its kind since US forces withdrew in December 2011.
Friday's violence struck across the country -- in Baghdad and to its north and south -- with gun and bomb attacks hitting both Shiite and Sunni areas.
In the deadliest attack, a suicide bomber detonated an explosives-rigged belt at a park in a crowded area of north Baghdad on Friday night, killing at least 25 people and wounding at least 36 others.
Militants have carried out a number of attacks at night in recent weeks, striking cafes and other places where crowds of people gather, to inflict maximum casualties.
Earlier on Friday, gunmen burst into a house in a mostly Shiite town north of Baghdad and killed three people, while violence in Hilla, south of the capital and also predominantly Shiite, left two dead.
And a half-dozen other separate shootings and explosions in Baghdad and in Mosul, a mostly Sunni Arab city in north Iraq, killed two people and wounded 12 others.
Meanwhile, a spokesman for a joint command centre in northern Iraq said security forces arrested seven Sunni militants linked to Al-Qaeda.
One of them was the self-styled finance minister of the Islamic State of Iraq and the Levant, an Al-Qaeda front group, who had reportedly tried to enter Iraq from neighbouring Syria with fake documents.
Unrest has surged in Iraq this year to levels not seen since 2008, when the country was emerging from a brutal Sunni-Shiite sectarian conflict that claimed tens of thousands of lives.
Attacks have killed more than 3,600 people since the beginning of 2013, according to figures compiled by AFP.
Analysts and diplomats link the increased bloodshed to anger among Iraq's Sunni Arab minority over their alleged ill-treatment at the hands of the Shiite-led government.
But the prime minister has vowed to press on with the security force operations, insisting they are producing results, while officials have hailed the arrest of hundreds of alleged militants and the killing of dozens of others.
Maliki issued two statements on Friday about violence in the region -- one condemning bombings in the north Lebanon city of Tripoli that killed dozens of people, and another calling for an investigation into alleged chemical weapons use in Syria.
Neither made any mention of the violence plaguing Iraq.
In addition to major security problems, the government in Baghdad has also failed to provide adequate basic services such as electricity and clean water, and corruption is widespread.
And political squabbling has paralysed the government, which has passed almost no major legislation in years.