Mortar attack on Baghdad camp kills three displaced Iraqis
Among those killed were two children, aged 10 and 16, the UN confirmed, when a mortar landed in the camp south of the capital.
Thirteen others were wounded in the attack that struck as displaced families prepared to celebrate Eid at the end of the Muslim holy month of Ramadan.
"We condemn this cowardly attack on a camp for displaced families, which has injured innocent civilians and killed children," Bruno Geddo, the United Nations refugee agency's Iraq representative, said in a statement.
It was "particularly cruel to target a camp holding vulnerable displaced families, who had already fled their homes to escape conflict and violence, in search of peace and safety", Geddo said.
More than 6,000 civilians currently reside at the camp after fleeing conflict areas across the country, UN figures suggest.
No group has yet claimed responsibility for the attack.
The Islamic State group's territorial gains in 2014 and a government offensive have forced millions of Iraqis to escape their homes - prompting a humanitarian crisis in the war-torn country.
More than 84,000 were forced to flee Fallujah when the the government launched an offensive against the IS bastion in May.
Last month, the United States announced it will co-host a donors conference in Washington on July 20 to fundraise for Iraqi civilians suffering in dire conditions.
"Due to the conflict and upheaval since January 2014, more than 3.4 million people are now displaced throughout Iraq and more than half are children," the State Department said in a statement. "Across the country, over 10 million people are in urgent need of lifesaving humanitarian assistance."
According to the statement, the UN humanitarian response plan calls for $861 million, however at present is only one-third funded.
"Over the coming months, humanitarian costs could climb to over $2 billion as potentially a million people are displaced from Mosul as military operations liberate Iraq's second-largest city" from the IS group, it added.