The death toll from a weekend attack in DR Congo's restive east rose to 21 on Monday, with the violence prompting aid groups to suspend their Ebola work in the area.
The bloodshed occurred on Saturday in Beni, a flashpoint city in North Kivu region. The Congolese army has blamed the Allied Democratic Forces (ADF), a notorious rebel militia.
The latest violence, which sparked local anger, comes just three months before the Democratic Republic of Congo holds a fractious election to choose a successor to Joseph Kabila, the country's deeply-contested president.
It also prompted NGOs in Beni working to fight the spread of Ebola to halt their work following a health ministry request, although Doctors Without Borders (MSF) was operating as normal in treatment centres some 30-50 kilometres (20-30 miles) outside the city.
Witnesses said Saturday's violence began in the city centre in the late afternoon with the attackers using guns and machetes.
An initial army estimate put the toll at 18 dead, including 14 civilians and four soldiers, but later raised it to 21, including 17 civilians.
Danger for the election
On Monday morning, many shops, schools and businesses in Beni remained closed in protest, and an opposition lawmaker called for "a rapid assessment of the army's operational effectiveness" ahead of December's elections.
"The front line is no longer in the Virunga National Park and is now in Beni, which poses a real danger for the holding of safe elections on December 23," said Anselme Mwaka, an opposition MP from the Union for the Congolese Nation (UNC).
Social networks buzzed with comments denouncing the apparent powerlessness of the army and perceived silence of the authorities.
"Kabila and his cronies dare to suggest that the situation is getting better yet these dramas are taking place every day. How can they live with this responsibility?" tweeted exiled opposition leader Moise Katumbi.
Patrick Nkanga Bekonda, a Kabila adviser, suggested there were local and external forces trying to provoke civil conflict in the troubled city.
"We can see the hallmarks of both local and external involvement in the 'Somalisation' of Beni, despite efforts to reduce these killings," he said.
Since January, Congolese troops have been engaged in a major military operation against the ADF but have not yet managed to stop the bloodshed in and around Beni.
The ADF is one of a number of armed groups that hold territory in the eastern DR Congo and are battling for control of the region's rich mineral resources.
The militia group, created by Muslim radicals to oppose of Ugandan President Yoweri Museveni, has been present in North Kivu since 1995. It has been accused of killing several hundred civilians over the past three-and-a-half years.