A brazen attack on the Iraqi justice ministry claimed by Al-Qaeda's Iraqi affiliate killed 30 people and wounded 50, state TV quoted justice minister Hassan al-Shammari as saying on Monday.
Security and medical officials had previously put the toll from the March 14 violence at 18 killed and 30 wounded.
The attack involved a series of mid-day bombings in central Baghdad's Allawi neighbourhood, adjacent to the heavily-fortified Green Zone, which is home to key government facilities and the American and British embassies.
As the bombs went off, militants stormed the ministry complex, clashing with security forces.
Accounts differed as to the success of the attack, but one official said two insurgents managed to detonate suicide vests inside the ministry building.
Violence in Iraq has decreased from its peak in 2006 and 2007, but attacks remain common, killing 220 people in February, according to an AFP tally based on reports from security and medical officials.
Assaults on heavily-defended targets such as the justice ministry are much rarer than the frequent bombings and shootings against civilians and security forces, but they do occur periodically, with targets including police stations, prisons and government offices.