Twelve militants linked to al-Qaeda have broken out of a prison in Basra in southern Iraq, the authorities say.
The men were awaiting trial when they obtained police uniforms and walked out of the detention centre - in one of Saddam Hussein's former palaces - before dawn, security officials said.
They are said to have ties with the Islamic State of Iraq - a Sunni insurgent group affiliated to al-Qaeda.
All the prison guards have been arrested and a manhunt is under way.
"Of course, there was collusion from within the compound, but we do not know who is involved at the moment," said Ali Ghanim al-Maliki, head of the security committee at Basra's provincial council.
The 12 were the only detainees held at the detention centre - in a fortified compound which also houses the governor's office, the police headquarters and an intelligence cell.
Half of them had confessed to involvement in multiple bombings since 2004 in Basra and the southern cities of Amarah and Nasiriyah, an intelligence officer told the Associated Press news agency.
Their confessions led the authorities to the other six suspects, the officer said.
He added that the fugitives were believed to be heading to Baghdad to obtain fake IDs and passports to help them flee the country.
Car searches and identity checks have been stepped up, and checkpoints set up on two major northbound roads.
Basra is Iraq's second largest city, located 340 miles (550km) south of Baghdad.