At least 20 children and nine aid workers are feared to be among the dead.
"I condemn these attacks in the strongest possible terms and demand that those responsible are held accountable," writes Clementine Nkweta-Salami in a statement.
The attacks targeted the Zamzam and Abu Shouk refugee camps and the city of al-Fashir in the state of North Darfur.
The RSF, together with allied militias, attacked the camps and the city from multiple directions on the ground and with artillery and drones.
The two refugee camps together house more than 700,000 people who have fled violence.
"This is yet another deadly and unacceptable escalation in a series of brutal attacks on displaced people and aid workers," writes Nkweta-Salami.
The RSF has been fighting against Sudan's regular army for two years. The country is effectively divided, with the army controlling areas in the north and east and the RSF with coordinated groups controlling areas in the west and south.
