More than 80 people are now reported dead in southern Iraq where so-called Islamic State claimed responsibility for three suicide attacks on Thursday.
The killers are said to have worn security force uniforms and driven stolen army vehicles as they targeted a police checkpoint and restaurants near the city of Nassiriya.
Hospital sources say at least 10 Iranian pilgrims, who were visiting holy Shi’ite shrines, are among the dead.
According to eyewitness Firas Ahmed: “There were four buses of Iranian pilgrims. The gunmen boarded and sprayed those inside with bullets, while others in pick-up trucks drove by, firing on the people.
“Then they walked into the restaurant, opening fire on those inside, the young and the old, sparing no one. Everyone here were killed.”
At least 100 people were injured, the police said in a statement.
ISIL claimed responsibility in a statement on its Amaq news agency. The group said it had killed “dozens of Shi’ites”.
The group’s activity is usually concentrated in western and northern Iraq. Bomb attacks in the mostly Shi’ite south have been relatively rare.
But Iraqi and Kurdish security officials say the Sunni militants are now likely to wage a guerrilla war after losing control of their former stronghold in Mosul.