A car bomb killed at least 20 people outside a Shia mosque north of Baghdad this evening as Iraqi leaders failed to make progress towards forming a national unity government they hope can avert sectarian civil war.
The explosion in the town of Howaydir was the latest in a wave of attacks against Iraq's Shia majority that Washington fears will push the country close to a full-scale communal conflict in the vacuum left by bickering politicians.
Fresh demands from the Shia Alliance over the creation of a government threatened to prolong the political paralysis.
Acting parliament speaker Adnan Pachachi said Iraqi leaders would discuss a national unity government at the next session on Monday and he was optimistic of a breakthrough before then in spite of the Shia Alliance's reluctance to drop its choice of Ibrahim al-Jaafari for prime minister.
"I spoke to the heads of all the political blocs and I sensed a true intent from all to push the political process forward," Pachachi said. "From now until the 17th of this month, we believe there will be an agreement on some of the problems."
Elections for the new government ended four months ago and the United States and Britain have been pressing Iraqi leaders to agree on who will lead it, fearful the widening vacuum emboldens insurgents trying to undermine the political process.
The car bomb in Howaydir exploded near a mosque and a crowded market, the kind of attack that U.S. and Iraqi officials say is part of a campaign by al Qaeda leader Abu Musab al-Zarqawi to draw Shias into civil war with Arab Sunnis.
Hospital officials said casualty tolls were expected to rise as ambulances were still rushing in with victims. Last week, a triple suicide bombing at a Shia mosque in Baghdad killed up to 90 people.
American military officials say Jordanian militant Zarqawi has shifted his tactics, attacking Iraqi army and security forces instead of US troops while continuing his bombings against civilians.
US military deaths in the Iraq war declined for a fifth straight month in March while insurgent attacks, aimed increasingly at Iraqis, continued unabated.
But rebels have killed eight US soldiers since Sunday in a series of incidents, including one struck by a roadside bomb on Wednesday.
he United States hopes the political process will defuse the insurgency and enable US soldiers to start heading home and has told Iraqi leaders its patience is running out.