The Rwanda-backed rebels who captured a major city in eastern Congo have sought to reassure its residents about their safety.

M23 rebels in the Democratic Republic of Congo said they would begin a unilateral ceasefire on Tuesday as the Group of Seven nations demanded that the Rwanda-backed militia halt an offensive that has shaken the eastern part of the country.

Officials and residents say Rwanda-backed rebels have gained ground in eastern Congo despite the unilateral ceasefire they declared earlier this week, taking control of a town 100 kilometers (60 miles) from the provincial capital of Bukavu.