At least 17 people were killed on Monday when heavy clashes erupted in Kinshasa ahead of an opposition rally, a Congolese minister said, calling the toll "provisional".
Among the dead were 14 civilians and three police officers, Interior Minister Evariste Boshab told a press conference in Kinshasa, capital of the Democratic Republic of Congo, describing the clashes as an attempted "uprising".
"By midday (1100 GMT), the sad and painful provisional toll from these barbaric and savage acts... (stood at) 17 dead, among them three police officers, one of whom was burnt alive, and 14 civilians who were involved in looting," he said.
It was the worst violence in the capital since January 2015, when security forces cracked down on rioters after another opposition demonstration spiralled out of control, in violence which left several dozen people dead.
"Kinshasa just experienced an uprising which ended in failure," the minister said, accusing demonstrators of "deliberately choosing" to ignore a schedule which had been agreed with the authorities
The main opposition parties had called for a nationwide demonstration on Monday to "give notice" to President Joseph Kabila some three months before his mandate expires on December 20 and to demand that presidential elections be held.
The demonstration in Kinshasa had been due to start at 1:00 pm, but during the morning, scuffles broke out between stone-throwing youths and anti-riot police which deteriorated into clashes.
Officials said there had been a spate of looting and that attempts to set fire to the offices of several mainstream political parties.
Private security officials also said there had been several looting incidents in the south of Kinshasa which targeted banks or Chinese-run shops.