Twin suicide bombings targeting Iraq's Shabak minority and fighting between security forces and militants killed 36 people in the northern province of Nineveh on Friday, officials said.
Provincial capital Mosul is one of Iraq's most dangerous cities, with well-entrenched militant groups carrying out almost daily attacks.
The two suicide bombers blew up vehicles in the Shabak village of Al-Muwaffaqiyah, east of the city, killing four people and wounding 45, police and medical officials said.
Most of Iraq's 30,000 Shabaks follow a blend of Shiite Islam and local beliefs viewed as heretical by Sunni extremists, and they have been periodically targeted for attack.
In west Mosul, four police, three soldiers and 16 militants were killed in clashes, while a mortar round killed a civilian, officials said.
Three more soldiers were killed in clashes with militants in east Mosul, while security forces shot dead five would-be suicide bombers in the Hamam al-Alil area south of the city.
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The violence came a day after militants launched a major attack on the city of Samarra, north of Baghdad, occupying multiple neighbourhoods.
Soldiers, police and tribal fighters backed by helicopters eventually regained control, a senior army officer said, but only after heavy fighting that killed 12 police and dozens of militants.
Violence is running at its highest levels since 2006-2007, when tens of thousands were killed in sectarian conflict between Iraq's Shiite majority and Sunni Arab minority.
More than 900 people were killed last month, according to figures separately compiled by the United Nations and the government.
So far this year, more than 4,300 people have been killed, according to an AFP tally.
Officials blame external factors for the rise in bloodshed, particularly the civil war in neighbouring Syria.
But analysts say widespread Sunni Arab anger with the Shiite-led government has also been a major factor.