Opposition supporters in the Democratic Republic of Congo blocked Kinshasa's roads with burning tyre as they called for President Joseph Kabila to stand down when his mandate ends on 19 December.
The country is required by its constitution to call a general election today. The opposition has said that the president will attempt to hold on to power.
"We want to tell Kabila that he must leave the presidency at the end of this term," opposition figure Freddy Matungulu told VOA Africa.
Kabila, who has run the DRC since 2001, sees his mandate expire on 20 December, and the constitution prohibits him from seeking another term. He does not appear, however, to show any signs that he wants to leave.
In May the constitutional court authorised Kabila to stay in his post beyond 20 December if no election had been organised in 2016.
The protests will centre around Etienne Tshisekedi, an emblematic opposition leader in the country, who has been able to build a coalition and bring together those opposed to Kabila.
That coalition has refused to participate in the 'national dialogue', which opened 1 September in Kinshasa under Africa Union mediators, with the objective of organising the next presidential elections. The opposition called the meetings "a trap" by the executive.
Human Rights Watch said in a report released on Sunday that "representatives of government and the security services should respect the human right to freedom of expression and assembly, and allow peaceful demonstrations and political meetings in DRC.
"The decisions that president Kabila and his government will take in the following weeks will make all the difference for the future of the DRC," it added.
On Thursday, Kinshasa said it was surprised by accusations levelled by Amnesty International that it is overseeing "systematic repression", saying that in August the authorities has freed several political prisoners.