GENEVA — Despite a peace agreement, mass atrocities continue in South Sudan, driven partly by fights over control of oil, and foreign oil companies may be complicit in war crimes, a United Nations panel said on Wednesday.

The United Nations Commission on Human Rights in South Sudan said it was “outraged by reports of thousands of civilians forcibly displaced following a scorched earth policy in which the parties to the conflict are attacking villages, torching homes, killing civilians and also raping women and girls,” Andrew Clapham, a member of the three-person panel, told reporters in Geneva.

A peace deal signed five months ago brought some hope to parts of South Sudan after five years of brutal conflict between President Salva Kiir’s forces and those loyal to his former deputy, Riek Machar, the panel said. But in a 216-page report it will submit to the Human Rights Council next month, the commission detailed continuing war crimes and crimes against humanity, and intensifying repression by the country’s security services.

Fighting between government forces and a rebel group, the National Salvation Front, in the south of the country had driven thousands of villagers to seek safety in nearby towns and thousands more to flee across the border into the Democratic Republic of Congo, Mr. Clapham said.