Iraqi authorities have recovered the bodies of 20 soldiers shot dead after being kidnapped from a northern military base, with 17 others also killed in a string of attacks.
The bloodshed comes as officials count votes from the country's April 30 general election amid a protracted surge in violence that has claimed more than 3200 lives this year.
Militants attacked the military base, abducted the soldiers and later shot them, according to security officers.
Their bodies were found in the area on Saturday night.
The powerful Islamic State of Iraq and the Levant (ISIL) jihadist group claimed the attack in a statement on Sunday, saying it had targeted members of the "Safavid army", a pejorative term to link Iraq's security forces with those of Iran, which was once ruled by the Safavid empire.
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"God willing, these operations will not stop," the statement added.
ISIL and an army major general said the kidnappings took place in Nineveh province on May 5.
The previous month, militants killed 12 soldiers and wounded 15 in an assault on a military base west of Mosul, the capital of Nineveh province.
Meanwhile, violence in Baghdad and north Iraq killed 17 people on Sunday, security and medical officials said.
Four policemen, two soldiers and a civilian were killed in attacks in Nineveh province, while one person was gunned down in Salaheddin province.
In Kirkuk province, gunmen killed a policeman and two soldiers.
Two people were shot dead in the capital, while four more people, including three anti-al-Qaeda militiamen, were killed on the city's outskirts.
