A suicide bomber attacked a Sunni funeral in Baghdad on Sunday, killing at least 12 people, Iraqi officials said, a day after bombings targeting Shiite mourners killed more than 70.
Medical and security sources said the bomber, who detonated explosives at a funeral tent in the Dura area of south Baghdad, also wounded at least 30 people.
The attack came a day after bombings against mourners in Sadr City, a Shiite area of north Baghdad, killed at least 73 people and wounded more than 200.
The United Nations on Sunday warned against revenge attacks for the Sadr City blasts.
"Retaliation can only bring more violence and it is the responsibility of all leaders to take strong action not to let violence escalate further," Gyorgy Busztin, the UN secretary general's deputy special representative for Iraq, said in a statement.
"Violence in all forms must be condemned, but I am particularly appalled by the increasing number of vicious attacks against those already bereaved," he said.
The Sadr City and Sunday's bombings were not the first targeting mourners in recent months.
They came after two bombs exploded on Friday at a Sunni mosque near Samarra north of Baghdad, killing 18 people.
Iraq was ravaged by a bloody Sunni-Shiite conflict that peaked in 2006-2007 and killed thousands of people.
There are persistent fears, bolstered by sectarian attacks this year, that Iraq may return to all-out conflict between its Shiite majority and Sunni minority.