At least 107 people are now dead following a wave of bomb attacks and shootings across Baghdad.
Officials say many of those killed were members of the security forces - who appear to have been a prime target.
They say one of the worst-hit places was Taji, a Sunni neighbourhood some 12 miles north of Baghdad, where at least 41 people were killed.
Some 13 Iraqi towns and cities were reportedly hit in the spate of apparently co-ordinated attacks.
Authorities in Iraq have described today as the deadliest day of the year.