RWANDAN-backed M23 rebels gained ground in eastern Democratic Rebublic of Congo (DRC) today, despite the unilateral ceasefire they declared earlier this week.

The M23 took control of Nyabibwe, a mining city 60 miles from the provincial capital of Bukavu, civil society officials and residents told reporters.

The M23 announced the ceasefire on Monday on humanitarian grounds after pleas for the safe passage of aid and hundreds of thousands of displaced people. 

But the DRC’s government described the ceasefire as “false communication,” with the United Nations noting reports of heavy fighting with Congolese forces in the mineral-rich region.

Nene Bintou, president of the civil society of South Kivu province, said Nyabibwe was under rebel control. The city is midway between Bukavu and Goma, the city the rebels seized last week and still control.

“We are worried about the situation,” said Moise Bisimwa, a resident reached by phone. “Apparently the ceasefire that was declared by the M23 is just smoke and mirrors.”

After seizing control of Goma, a provincial capital of 2 million people at the heart of a region home to trillions of dollars’ worth of mineral deposits, the rebels were reported to be gaining ground in other areas of eastern DRC and advancing on Bukavu.

The militia on Monday said they did not intend to seize Bukavu or other areas, though they earlier expressed ambition to march on Congo’s capital, Kinshasa, a thousand miles away. 

“However, we reiterate our commitment to protecting and defending the civilian population and our positions,” M23 spokesman Lawrence Kanyuka said.

The M23 are backed by some 4,000 troops from neighbouring Rwanda, according to UN experts, far more than in 2012, when they briefly captured Goma then withdrew after international pressure. 

The M23 are one of the more than 100 armed groups active in DRC’s east, which holds vast deposits critical to much of the world’s technology.

Rwanda’s President Paul Kagame told CNN on Monday that he didn’t know the whereabouts of his forces, but said his country would do what’s needed to protect itself.

In Goma, where Congolese authorities have said over 2,000 have been killed since the city was seized, residents continued to bury bodies.

The UN humanitarian coordinator for DRC, Bruno Lemarquis, has called for the urgent reopening of the airport in Goma, “a lifeline” for the evacuation of wounded people and delivery of aid.