A series of bombs exploded in Baghdad, killing at least 31 people and leaving more than 50 others injured, in the first major attacks in Iraq in nearly a month.
(CNN) Baghdad - In a separate incident in Kirkuk, two car bombs exploded, killing four people and injuring 23 others, including six police officers.
The violence may continue a pattern of outbreaks following lulls.
March had the lowest monthly death toll since the U.S-led invasion in 2003, officials said earlier this month.
According to interior ministry figures, 112 people died violently in March: 78 civilians, 12 Iraqi soldiers and 22 police officers.