The Rwandan-backed M23 armed group in Democratic Republic of Congo threatened on Tuesday to advance on the provincial capital of Bukavu, citing a "dangerously deteriorating" situation, as Congo rejected a call for direct talks with the rebels.

The takeover of Bukavu would constitute an unparalleled extension of territory under the M23’s control, as well as a further blow to Kinshasa’s authority in eastern Congo following the collapse of Goma,

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.