Iraqi figures estimate civilian deaths in violence across the country rose by 13% last month, despite the security crackdown in Baghdad.
Tighter security seems to have brought some results in Baghdad
Data compiled by several ministries put civilian deaths in March at 1,861 - compared with 1,645 for February.
A BBC correspondent in Baghdad says insurgents seem to have shifted their focus outside the capital to avoid recently introduced security measures.
US diplomats say violence in the Iraqi capital has fallen by 25%.
In renewed violence on Sunday, two truck bombs exploded in the northern city of Mosul, killing two people and injuring 17 others, Reuters news agency reported.
And the US military said six of its personnel were killed in roadside bombings south-west of Baghdad over the weekend.
The six-week old security push seeks to significantly reduce sectarian violence in Baghdad, which is seen as crucial to stabilising Iraq as a whole.
Although much of the violence in March was outside Baghdad, the capital still saw big attacks.
The northern town of Talafar was a focus of violence in the past week.
A suicide truck bombing which left at least 83 people dead was followed by apparent revenge attacks against Sunnis that killed at least 45 people.
US military commanders had expected a switch in tactics, and the latest figures released by the interior, defence and health ministries appear to bear that out, says the BBC's Jonathan Charles in Baghdad.
According to the data released, 165 Iraqi police and 44 Iraqi soldiers were also killed in March.
More than 80 US service personnel lost their lives over the same period.
Health ministry estimates for civilian deaths in violence in January and December were both more than 1,900.