A raid by Iraqi troops on a camp housing members of an exiled Iranian opposition group has left four people dead and more than 400 wounded.
The Iraqi army had stormed Camp Ashraf to the north of Baghdad on Tuesday, but were forced to call in riot police to quell the violence when residents tried to resist.
Iraq's defence ministry said the offensive against the People's Mujahedeen base was justified under a security agreement signed by Baghdad and Washington in November.
"It's our territory and it's our right to enter, to impose Iraqi law on everybody," General Mohammed Askari, the defence ministry spokesman told Al-Arabiya television.
The offensive followed a declaration by the People's Mujahedeen that it was ready to return to Iran if the authorities there would guarantee its members would not be abused.
A police official said that at least 300 people, including 25 women, had been injured.
About 110 members of the Iraqi security forces were also wounded in the violence, he said, and more than 50 camp residents were detained.
Some 3,500 People's Mujahedeen supporters and their families live in Camp Ashraf.
Salah al-Mutlaq, an official from the Iraqi National Dialogue Front described the offensive as "stupid" from the part of the Iraqi government.
"There are priorities much more important than this. They [Iraqi security forces] should guard the banks and their borders with Iran instead of confronting these armed men." al-Mutlaq told Al Jazeera.
"It is very difficult to have an explanation for what was done, if anything it was a step to please the wishes of the Iranian regime.
"I don't think they can hand them [the prisoners] over to the Iranian regime because that’s absolutely against the law and against the security agreement between the US and Iraq."
A France-based spokesman for the National Council of Resistance of Iran, which includes the People's Mujahedeen, called the raid "a crime at the request of and for the pleasure of the Iranian supreme guide."
"We are so worried that they might take the people arrested to the Iranian regime and hand them over," Shahriar Kia, a Mujahedeen spokesman said by telephone from Camp Ashraf.
The Iranian government accuses the People's Mujahedeen of playing a a key role in fomenting the deadly protests which followed last month's disputed re-election of Mahmoud Ahmadinejad, the Iranian president.
However, Ian Kelly, the US state department spokesman, said that the Iraqi government had "stated to us that no Camp Ashraf resident will be forcibly transferred to a country where they have reason to fear persecution."
The People's Mujahedeen was founded in 1965 in opposition to the Shah and has been fighting to oust the clerical regime which took power in the 1979 Islamic revolution.