UN Secretary General Ban Ki-moon has condemned the commandeering of humanitarian vehicles and theft of relief items in South Sudan, a spokesman said Wednesday. Both government and anti-government forces were involved in the thefts, Ban said. UN spokesman Martin Nesirky could not provide any figures for hijacked vehicles or the amount of stolen supplies, but emphasized that any act that hampers the delivery of aid to needy people was "utterly unacceptable." Ban has also been alarmed by rising number of displaced people in the country, which surpassed 400,000 this week, the UN said in a statement. Nesirky also provided details about a UN peacekeeper who was injured after heavy fighting erupted between pro- and anti-government forces in the vicinity of a UN compound in town of Malakal on Tuesday. Earlier the UN mission in South Sudan had said that dozens of civilians were wounded when stray bullets landed in its Malakal compound. The gunfire also killed a young civilian inside the base.