The rebel March 23 Movement in the Democratic Republic of Congo mutinied during the spring. By U.N. estimates, about 390,000 people in DRC were displaced internally and another 60,000 fled to neighboring Rwanda and Uganda since the rebellion.
Human Rights Watch had said M23 is likely responsibly for war crimes in the country.
Martin Ohlsen, the WFP representative in DRC, said most refugees left their only source of food and income when they were forced to flee the violence.
"It's important not to forget that this crisis in the east (of the country) is taking place in one of the poorest countries in the world, where 5.4 million people were already facing chronic hunger and malnutrition," he said in a statement.
WFP said it embarked on an emergency program through June 2013 to provide assistance to roughly 1.2 million people in DRC.