"All relevant actors should discourage returns until the violence subsides and people can receive adequate assistance and protection," Refugees International said in a report on Iraqi refugees and internally displaced people. "In particular, the government of Iraq should not use returns as an indicator of success in stabilizing the country."

The humanitarian relief organization based in Washington said the Iraqi government and international community failed to meet the needs of the refugees and displaced, forcing "non-state actors" to step in to help.

"Militias of all denominations are improving their local base of support by providing social services in the neighborhoods and towns they control," the report said. "(The) Shiite Sadrist movement has established itself as the main service provider in the country."

Similarly, other Shiite and Sunni groups have gained support through providing food, oil, electricity, clothing and money to vulnerable Iraqis living in their territories, the report said.

"For Iraq to have any future," the report said, "international donors must ensure that resources are allocated to the humanitarian response, and that all appeals are fully funded."