The Rwanda-backed rebels who seized a major city in eastern Congo have declared a unilateral ceasefire, citing humanitarian grounds. Monday's announcement came after the U.N. health agency said at least 900 people had died in last week's fighting between the M23 rebels and Congolese forces after the rebels seized the major city

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.

The international community must take concrete action and impose sanctions on Rwanda to curb the M23 rebel conflict in eastern Congo and keep the peace in the wider region, Congo's communications minister told Reuters on Monday.