Iraq's prime minister has offered a general amnesty to Sunni tribes fighting the central government, in an attempt to undercut support for a rebellion that threatens the country's unity.
Nouri al-Maliki made the surprise call in his weekly televised address on Wednesday, urging fighters to "return to their senses".
"We are not excluding anybody, even those who committed misdeeds, apart from those who killed or shed blood," he said.
It was not immediately clear how many people might be eligible, but the move appeared to be a bid to split the alliance of religious fighters, Baath party loyalists and anti-government tribes.
Maliki also gave warning on the threat posed by the Islamic State, saying that "no one in Iraq or any neighbouring country will be safe from these plans".
He said the group's call for re-establishing a "caliphate" meant all the states in the region were a target and "inside the red circle".
Maliki's comments came a day after a chaotic opening to the new parliament, despite international leaders urging Iraq's fractious politicians to unite to help combat the rebels.
Iraq's parliament reconvened on Tuesday before descending into chaos as politicians traded heckles and threats.
Sunni and Kurdish MPs stayed away from voting, meaning a speaker could not be elected as constitutionally required.
International leaders had warned Iraq's politicians of the threat with the US reminding that "time is not on Iraq's side", and Marie Harf, the State Department spokeswoman, calling for "extreme urgency".
Nickolay Mladenov, the UN special envoy, said Iraqi politicians needed "to realise that it is no longer business as usual".
Fighters from the Islamic State group, formerly known as ISIL, announced on Sunday they had unilaterally established a caliphate in the areas under their control.
The group declared Abu Bakr al-Baghdadi the new caliph and demanded that all Muslims pledge allegiance to him.
Since the announcement, Abu Muhammad al-Maqdisi, the Jordanian Salafist religious leader, and the pan-Islamist group Hizb ut-Tahrir have rejected the claim as "empty speech without substance".
Hizb ut-Tahrir dismissed the declaration of a caliphate, saying the Islamic State group had no real "authority" in implemeting Islamic rule.
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The Sunni offensive which has allowed the Islamic State to take territority from the government is prompted by a long list of grievances with Maliki and his Shia-led government.
They accuse Maliki of treating them like second-class citizens and unfairly targeting them with the security forces.
Since the rebellion started nearly 900 Iraqi security personnel have been killed, and Iraqi forces have been struggling to break a stalemate despite offensives by thousands of troops, backed by tanks, artillery and aerial cover.
Clashes between supporters of an outspoken Shia religious leader and Iraqi police killed up to 45 people in the Shia holy city of Karbala, the Reuters news agency said.
The violence started late on Tuesday night when supporters of Ayatollah Sayyid Mahmud al-Hasani al-Sarakhi were prevented from marching on the Imam Hussein shrine by Iraqi security forces, who were supported by helicopters.
Al Jazeera's Imran Khan, reporting from Baghdad on Wednesday, said Sarakhi had criticised other religious leaders in Karbala for being under Iranian influence.
"His supporters have had enough of Sistani," our correspondent said, referring to the most revered religious figure in Iraq, Grand Ayatollah Ali al-Sistani, who recently called on Iraqis to support the government in its fight against Sunni rebels.