The United Nations says M23 rebels have enforced an “unacceptable” curfew in areas under their control in the east of the Democratic Republic of Congo."The M23, which in practice controls the territory of Rutshuru (north of Goma)," has "imposed a curfew on civilians," the spokesman of the UN mission in Congo, known as MONUSCO, said on Wednesday. Felix Basse said this was "completely unacceptable" and the situation was "being monitored by UN troops until future action." Earlier in the day, UN Special Envoy to Congo Mary Robinson said that the peace talks between the Congolese government and the M23 rebels could yet succeed, adding the negotiations were not "at an impasse." She made the remarks during a press conference in the Congolese capital Kinshasa. On August 31, M23 rebels warned that they will resume fighting in the east of the country if the government refuses to halt its military offensive and start negotiations. On August 30, the Congolese army captured strategic hills overlooking the city of Goma in the east after M23 fighters pulled out from the area. A day later, the M23 rebels, who defected from the Congolese army in April 2012 in protest over alleged mistreatment in the army, issued a statement saying that their decision for a “unilateral ceasefire” and withdrawal was aimed at "creating a favorable climate" for a "political solution to the crisis". "We demand that the Congolese government return soon to the negotiating table to find a political solution to the crisis," said Bertrand Bisimwa, the president of the rebel movement. The talks between Kinshasa and the M23 began in December 2012 but broke down in April 2013. The M23 rebels and several other armed groups are active in eastern Congo and are fighting for control of the country’s vast mineral resources, such as gold, the main tin ore cassiterite, and coltan (columbite-tantalite), which is used to make many electronic devices, including cell phones. Since early May 2012, nearly three million people have fled their homes in eastern Congo. About 2.5 million have resettled in Congo, but about 500,000 have crossed into neighboring Rwanda and Uganda.