Police on Sunday dispersed hundreds of anti-government marchers in Kinshasa and a protester was shot dead in the eastern city of Goma after President Felix Tshisekedi -- the son of opposition icon Etienne Tshisekedi -- warned against "confusing democracy with anarchy".
Police and organisers said the protester died after being shot at a banned march in Goma.
"One person seriously wounded by gunshot died in hospital," national police spokesman Pierrot Mwanamputu told AFP, while an opposition youth official said: "They fired real bullets."
In Kinshasa, police used tear gas to break up another banned march and around 50 officers blocked a car transporting former presidential candidate Martin Fayulu and ex-prime minister Adolphe Muzito.
An AFP journalist saw police using bayonets to puncture three of the car's tyres.
The two men emerged from the car to talk to Kinshasa police chief Sylvano Kasongo as some demonstrators tried to group around them.
On Saturday, President Tshisekedi backed a decision to ban the march planned by his onetime fellow travellers, pointing to violence that broke out last weekend.
Speaking in his first major interview since taking office early this year, Tshisekedi told French media: "We have the impression that there are some who confuse democracy with anarchy."
Last Sunday, as opposition leader Jean-Pierre Bemba flew back into the country, police fired tear gas at rock-throwing protesters who targeted his convoy.
Before being elected president, Tshisekedi inherited the mantle of opposition leader from his father Etienne, who died in February 2017.
Sunday's march was called by Bemba and Fayulu, who maintains that he was robbed of victory in the December 30 presidential election in the former Belgian colony.
Their Lamuka coalition said late Friday it would go ahead with the march to protest the constitutional court's invalidation of the election of about 20 opposition lawmakers.
Kasongo had warned that any gatherings of more than 10 people Sunday would be dispersed.
Fayulu, 62, accuses Tshisekedi of being the "puppet" of his predecessor Joseph Kabila, whose party enjoys a majority in parliament.
A former vice president, Bemba ran unsuccessfully for the presidency against Kabila in 2006.
He was then jailed by the International Criminal Court based in The Hague for alleged atrocities carried out by his troops in the Central African Republic.
But he was finally acquitted and freed on appeal in June 2018, when he returned to Belgium.
Fayulu insists he lost the presidency only because a deal was agreed between outgoing president Kabila and Tshisekedi.