The U.S. Treasury Department said it targeted two companies linked to Sudan's army and two companies tied to the rival paramilitary Rapid Support Forces .
Residents said heavy artillery fire could be heard in northern Omdurman and intermittent firing in southern Bahri. The companies, which are all key to the business and procurement activities of both forces, could not immediately be reached for comment. In the city of Zalingei, it said that city's hospital and university were looted and people were being killed "randomly".
Food and assets were being looted in El Obeid, a regional hub to the southwest of Khartoum, the World Food Programme said. "Food for 4.4 million people is at stake," agency chief Cindy McCain said.