The troops - from Uganda, Kenya, Burundi and South Sudan - have begun flying home, after President Félix Tshisekedi refused to extend their stay and top officials criticised their performance.

Soldiers from the Southern African Development Community (SADC) bloc are expected to replace the East African force, but no date has been set for their arrival.

In a related development, the M23 rebel group has captured the town of Mushaki which is 40km (25 miles) from Goma, the capital of the mineral-rich Nord Kivu province.

The rebels seized the town on 7 December after clashing with the Congolese army. Mushaki is a key transport hub in the region and has changed hands between the M23 and the army several times.

DR Congo is scheduled to hold a general election on 20 December.