Kidnappers who abducted scores of Iraqis from an education ministry building in Baghdad have tortured and killed some of them, a government official said today.
Basil al-Khatib, a higher education ministry spokesman, said details of the hostages' ordeal had been revealed by people who had been freed.
Mr Khatib was speaking after the escalating violence in Iraq claimed the lives of at least 18 people, including four US soldiers.
Up to 150 employees and visitors were kidnapped on Tuesday by around 80 gunmen who stormed the four-storey ministry building. Around 70 have since been released.
"Some of the hostages were tortured and killed, according to eyewitnesses from among the captives who were released," Mr al-Khatib said. He added that it remained unknown how many of the hostages had been tortured and murdered.
The education minister, Abed Theyab - a member of a Sunni Arab party in Iraq's Shia-led government - has reiterated his decision to boycott the government until all the hostages are released, Mr al-Khatib said.
Shia militia are suspected of having carried out the kidnappings.
In today's deadliest attack in Baghdad, gunmen opened fire on a bakery, killing nine people, police said. Such attacks are usually carried out by Sunni Arab militants because most bakeries in the capital are run by people from the Shia majority.
Employees and customers of the bakery died in the attack, which happened in the eastern Zayouna neighbourhood at 7.30am local time (0430GMT), police said.
Three civilians and two Iraqi policemen were killed in four other attacks in Baghdad this morning.
A roadside bomb killed two US soldiers yesterday, while two others were killed by small arms fire during combat operations, the military said.
The two soldiers who died in the bombing were assigned to 3rd Brigade Combat Team, 1st Cavalry Division, and were killed while on combat operations in Diyala province in north-eastern Iraq, the military said.
Also yesterday, another soldier from the same combat team was shot and killed by small arms fire while in action in Diyala. On Tuesday, a soldier from the army's multinational corps was killed by small arms fire during an operation in Baghdad, officials reported today.
Elsewhere, US ground and air forces killed nine suspected al-Qaida insurgents during a raid in Youssifiya, a rural area around a dozen miles south of Baghdad, military officials said.