Last-ditch talks led by Congo's Catholic bishops went into overtime on Saturday only days ahead of a deadline for President Joseph Kabila to step down from power or risk setting off a political crisis.
The country's Catholic episcopal conference, CENCO, had initially set a Friday deadline to get the government and opposition to agree on a transition for the country after Kabila's second and last legal term expires on Tuesday.
An election for a new Democratic Republic of Congo head of state was supposed to have been held this year, but the authorities failed to organise the polls.
The 45-year-old president, who stepped into his assassinated father's shoes in 2001, is barred from a third mandate under the constitution.
Opponents accuse him of delaying the vote in the hope of tweaking the constitution to extend the Kabila family's hold over a nation hugely rich in minerals that is almost the size of western Europe.
The CENCO-sponsored talks launched early this month pit the ruling party and fringe opposition groups against a mainstream opposition coalition headed by veteran Kabila rival, Etienne Tshisekedi, who is 84.
Mediators reconvened talks with both sides Saturday morning, but their time is short: the bishops leave Saturday evening for a long-planned visit to see Pope Francis.
Eve Bazaiba, head of the opposition MLC group, urged Kabila's camp to "cease with its smug sense of superiority and its arrogance, and allow for a settlement of the dialogue" in time.
The main sticking point in any future deal is the political fate of Kabila, who has announced only his intention to remain in power until a successor is chosen in an election.
The international community has warned the current tension could lead to spiralling violence.
Some two decades ago, Congo sunk into the deadliest conflict in modern African history, its two wars in the late 1990s and early 2000s dragging in at least six African armies and leaving more than three million dead.
A democratic handover would break ground for Congo's 70 million people who since independence from Belgium in 1960 have never witnessed political change at the ballot box.
In the last few years hundreds of people have died in political violence in the capital, Kinshasa, and elsewhere.
Tshisekedi and his allies had threatened nationwide protests from Monday to press Kabila to step down, but have opted to hold off pending the negotiations.
The government for its part has ordered that social networks including Facebook and WhatsApp be blocked from 11:59 pm (2259 GMT) on Sunday.
Police set up road checkpoints in Kinshasa, while the Republican Guard patrolled the capital's administrative district Saturday near the presidential palace, AFP journalists reported.
The church mediators have warned that failure to find a political settlement ahead of December 20 would lead to "an uncontrollable situation". Western diplomats in Kinshasa have urged their nationals to leave the country.
