At least 21 people were killed when two bombs exploded on Saturday evening near Sunni mosques in the Iraqi capital Baghdad, the BBC reported.
The attacks took place as worshippers were congregating to pray, having broken their fast for Ramadan.
16 people were killed when a bomb went off near a mosque in the southern Dora area of the city, whilst a car bomb near in the Jamia district of western Baghdad left at least five people dead.
The Baghdad blasts come a day after a cafe bombing in the norhtern city Kirkuk left 38 people dead.
Sectarian violence has ripped across Iraq in recent months, amid growing fears that the country may be returning to the levels of bloodshed seen during 2006-2007.
More than 2,500 people have been killled in the country since April, according to a United Nations report.