A series of bomb attacks in Baghdad killed at least 58 people and wounded more than 100 on Friday.
The blasts came days after US and Iraqi officials claimed to have dealt a significant blow to al-Qaeda in Iraq by killing two of its senior leaders.
The bombs targeted mainly Shia neighbourhoods, including a market and areas close to mosques as worshipers gathered for Friday prayers. The aim appears to have been to stir sectarian violence.
Several bombs also exploded in Anbar, the predominantly Sunni Arab province west of the capital, killing at least seven people.
Extremists have stepped up their attacks as politicians wrangle over the creation of a new coalition government in the aftermath of last month’s elections.
The attacks are blamed on al-Qaeda-linked militants and members of Saddam Hussein’s old Ba’ath party.
“Targeting prayers in areas with a certain majority is a revenge for the losses suffered by al-Qaeda,” said Major-General Qassim al-Moussawi, an Iraqi security spokesman, referring to the attacks in Shia areas.
On Monday, US and Iraqi officials announced the deaths of two senior al-Qaeda figures in Iraq. General Ray Odierno, commander of US forces in the country, described this operation as “potentially the most significant blow to al-Qaeda in Iraq since the beginning of the insurgency.”
A day later, a third suspected al-Qaeda leader was killed by Iraqi security forces.
However, the attacks on Friday underlined the continuing threat. Analysts fear that extremists will try to take advantage of the post-election political uncertainty.
Iraqiya, a secular coalition dominated by Sunni Arabs and led by Iyad Allawi, a former prime minister, came first in the poll by the slender margin of two seats. But no group has an overall majority in the 325-member parliament, meaning that lengthy talks to form a new coalition government are now underway.
Earlier this week, a panel investigating election complaints ordered a manual recount of the votes cast in Baghdad, a decision which could change the election’s outcome.
But US officials say they plan to withdraw their troops on schedule. American forces are due to be cut almost by half to 50,000 by the end of August, with a complete military departure planned for the end of 2011.