The blasts causes massive damage in central Baghdad
A militant group linked to al-Qaeda has claimed responsibility for two car bombs which killed more than 150 people in Baghdad on Sunday.
The Islamic State of Iraq said its suicide bombers had targeted "dens of infidelity" in the Iraqi capital.
The massive blasts hit the ministry of justice and a provincial government office near the heavily fortified Green Zone, causing extensive damage.
The claim, posted on the internet, could not independently verified.
The Islamic State of Iraq, an umbrella organisation of radical Sunni militants, said it had targeted "the ministry of oppression, known as the ministry of justice, and the Baghdad provincial assembly".
ISLAMIC STATE OF IRAQ
Sunni insurgent umbrella group opposed to the Iraqi government
Formed in late 2006 to establish a Islamic state in its place
It is affiliated to the global al-Qaeda movement
It says it was behind the October 2009 bombings in Baghdad that killed over 150 people
It also said it carried out the August 2009 attack on the finance, foreign and defence ministries that killed nearly 100 people
"The enemies only understand the language of force," it said in a statement.
The massive attack was the deadliest in Iraq since August 2007.
Suicide bombers blew themselves up as senior politicians were meeting to try to break the deadlock over a draft law that would enable elections to take place next January.
Iraq Prime Minster Nouri Maliki said there was a "wicked political will" behind the attacks.
"We are facing big challenges in the reconstruction process, but while we are building, they are destroying," he said, in an address at Baghdad university on Monday.
The attacks came three months after the US handed security control of cities to local forces, raising concerns that Iraq could not protect itself.
Mobile footage captures blast in the Iraqi capital
Iraqi Foreign Minister Hoshiyar Zebari said the attacks showed that increased international support for the country was "vital and important".
The blasts drew comparison with an attack on 19 August, also claimed by the Islamic State of Iraq, in which truck bombs hit two ministry buildings and killed at least 100 people.
Iraq then blamed foreign fighters and accused Syria of involvement, demanding a UN investigation.
Mr Zebari said Sunday's blasts had strengthened that request for "a senior international envoy to come to Iraq and evaluate the degree of interference targeting stability in Iraq".
The US state department said it would support a United Nations investigation into "very serious allegations" of foreign involvement in Iraqi violence.
"What happened was so utterly horrific that the circumstances surrounding it need to be looked into," spokesman Ian Kelly was quoted by Reuters news agency as saying.
Overall, violence has dropped dramatically in Iraq compared to a year ago, but sporadic attacks still continue in several parts of the country.
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