Baghdad (CNN) -- At least nine city and provincial officials were among dozens killed when armed militants took over a government building in Iraq and held hostages this week, Interior Ministry officials told CNN Wednesday.
At least two journalists, including CNN contributor Sabah al-Bazi, were among the dead when armed men assaulted and seized the building in Tikrit in northern Iraq on Tuesday.
At least 56 people died and 98 others were wounded in the attack, which ended after Iraqi forces launched a raid to take back the building and free the hostages.
The United States condemned the "senseless and brutal attack" in a statement on Wednesday.
The embassy in Baghdad called it "an attack on the very foundations of democracy that Iraqis have strived so valiantly to build."
The armed militants, clad in police uniforms, clashed with the Iraqi police, and a suicide car bombing also was reported in the fighting in Tikrit, the capital of Salaheddin Province.
Three provincial council members were among the dead, as were six city council members from the nearby town of Shirqat, officials said.
Overall violence in Iraq has dropped drastically over the past three years, and the insurgency there has received devastating blows. However, Tuesday's assault shows that Iraq remains an unstable country and insurgents are still able to carry out deadly attacks.
"This coordinated attack in Tikrit bears the hallmark of al Qaeda in Iraq, and the attackers were planning to take all members of Salaheddin Provincial Council as hostages," a senior official with Tikrit police told CNN on condition of anonymity because he is not authorized to speak to media.
Al-Bazi was a freelancer who worked with Reuters, CNN and Al-Arabiya, according to his cousin Mahmoud Salih, also a freelance journalist.
Salih -- who said al-Bazi died in the car bombing -- told CNN his cousin contacted him 30 minutes before he died, asking him whether he wanted to film ammunition seized by security forces.
A number of gunmen inside the building were wearing explosive vests, and at least two of the attackers detonated their vests as Iraqi security forces approached, Tikrit police said.
Dozens of employees were held hostage inside the building, which houses the provincial council and other government offices.
Local TV in Tikrit showed video of smoke rising from the building, surrounded by Iraqi security forces, and aired the sounds of heavy gunfire.
The tactics were similar to an attack on a church in Baghdad in October, when gunmen took dozens of hostages, detonated suicide belts, and killed and wounded scores of people.
Authorities in Salaheddin announced a three-day mourning period for the victims of Tuesday's attack.
A U.S. military spokeswoman said American troops "assisted Iraqi security forces with securing the site of the attack and were providing aerial observation and surveillance in support of Iraqi forces on the ground."
The United States is set to withdraw all of its troops from Iraq at the end of the year in a bilateral agreement with the Iraqi government. However, it is too soon to predict whether the United States and Iraq will negotiate an agreement to keep some U.S. soldiers there after year's end.