Plumes of smoke were seen rising in Baghdad on Sunday morning after two vehicles packed with explosives blew up just outside the Green Zone, the heavily-fortified administrative heart of the capital.
"The walls collapsed and we had to run out," Yasmeen Afdhal, a 24-year-old employee at the Baghdad Governorate told AP news agency.
Iraqi officials say the number of dead and wounded is likely to rise, as rescue workers dig through the rubble to search for survivors.
"We're a few miles off but we could feel the force of those explosions," says the BBC's Gabriel Gatehouse in Baghdad.
Our correspondent says it is too early to determine who is behind the attacks, but that the finger of blame is likely to point to insurgents or foreign fighters trying to destabilise the security situation ahead of Iraqi elections in mid-January.