Rebels in South Sudan seized control of the key city of Bentiu, the capital of the oil-rich Unity State, the government announced Sunday. The government insisted it is still in control of the nation’s oil fields—and nearly 99 percent of the country’s revenue comes from oil. Bentiu is now in the hands of an army commander who has declared loyalty to former Vice President Riek Machar, who is now a rebel leader. Clashes began in South Sudan’s capital, Juba, last week between forces loyal to Machar and others who remained in support of President Salva Kiir. Kiir has accused Machar of staging a coup, and Machar has accused Kiir of purging Machar’s allies.