Rwandan-backed rebels who have swept through eastern Congo this week met resistance from the army and its allies including Burundian troops as they tried to push south on Friday, a Congolese official and another source said.

The Democratic Republic of Congo's electoral body has accused the Rwandan army and M23 rebels of looting polling office facilities in Goma, a city in eastern Congo. The Independent National Electoral Commission said Thursday that “members of the Rwandan army and their M23 supporters” looted the Provincial Executive Secretariat facilities and warehouses in Goma on Tuesday and Wednesday.

Democratic Republic of Congo President Felix Tshisekedi, speaking publicly for the first time since Rwandan-backed rebels seized the eastern city of Goma, said his government was preparing a response and warned of “unpredictable consequences” for the region.