At least 35 people were killed Wednesday when a suicide bomber blew himself up among a crowd of mourners north of Baghdad, reported dpa.
The attack occurred in the town of Tuz Khurmato, some 175 kilometres from the Iraqi capital. A further 75 people were injured, security officials said.
It comes a day after 21 people were killed in a series of attacks across central and northern Iraq.
The latest surge in violence comes amid a festering crisis pitting the Shiite-led government and the country's formerly dominant Sunni minority.
Thousands of Sunni protesters have been rallying for more than three weeks against Shiite Prime Minister Nuri al-Maliki, demanding a repeal of laws they claim target Sunnis.
Iraq has witnessed near-daily attacks since US troops withdrew in December 2011, raising fears of a return to the sectarian tensions that drove the country close to civil war in 2006 and 2007.