Police officials say that the blast happened today morning in the capital's western suburb of Abu Ghraib killed four people and wounded 12 others.
Also, police said that attackers using guns fitted with silencers killed three off-duty policemen in a drive-by shooting near Fallujah, 65 kilometres west of Baghdad.
Health officials confirmed the casualties. All spoke anonymously because they were not allowed to brief reporters.
The new violence came a day after a series of deadly attacks that left 19 dead. Violence has been on the rise in Iraq recently amid political and sectarian tension.