|Some 18,500 candidates, representing more than 417 parties, have registered for legislative elections [Reuters]
At least three people have been killed in the Democratic Republic of Congo's capital Kinshasa after riot police used tear gas and live fire to disperse government and opposition supporters attending campaign rallies.
Saturday's clashes came as campaigning came to a close, two days before presidential and parliamentary elections in the vast central African nation.
There were bouts of rock-throwing between opposing supporters and brief bursts of gunfire, reporters said.
Al Jazeera's Yvonne Ndege, reporting from Kinshasa, said "thousands of supporters" had tear gas fired on them, adding that the "feeling among the opposition is that this is a sign of how popular the opposition are and that [President Joseph] Kabila can't win Monday's elections".
Daniel Howden, Africa correspondent for the UK newspaper, The Independent, said on Twitter: "Live rounds and tear gas" were being used "at large crowds in Kinshasa airport".
Al Jazeera has not been able to independently verify the account.
President Joseph Kabila and two of his main challengers, Etienne Tshisekedi and Vital Kamerhe, were all due to hold campaign rallies within several hundred metres of each other later on Saturday.
Concerns on logistics
The stand-off between riot police and protesters took place near the central Kinshasa stadium where Kabila was due to appear, but violence was also reported at the airport where Tshisekedi was followed by supporters and the media, said our correspondent.
It was the latest sign of tension in the run-up to Congo's second presidential election since a 1998-2003 war, a poll which has been marked by opposition allegations of irregularities and concerns that voting arrangements will not be in place in time.
Despite a logistics operation supported by helicopters from South Africa and Angola, it is not clear whether all the ballot slips will have reached the 60,000 voting stations in the thickly-jungled country two-thirds the size of the European Union.
Tshisekedi said he could accept a delay but only if the head of the national election commission, who he accused of having political ties with Kabila and turning a blind eye to alleged irregularities, was sacked.
"I would agree [to a delay] if that meant a more credible, democratic and transparent process," the 78-year-old veteran opposition leader told French RFI radio.
"But one thing is clear: if we say there will be a delay, it is clear that the election commission cannot be led by Daniel Ngoy Mulunda," he said, accusing him of having been a founding member of Kabila's PPRD political party.
Local media reported earlier on Saturday that Tshisekedi would hold his rally on a nearby boulevard, but the proximity of the two venues still raised concerns.
Lack of transparency
"The latest news is that they will all be holding their meetings very close to each other, so let's hope that in the afternoon everything will pass peacefully," said Dirk Koch, director of international organisation Search for Common Ground, who is running an anti-violence campaign ahead of the elections.
The UN Security Council, the European Union (EU) and other Western governments have all voiced concern at violence in the run-up to the vote and called for candidates to avoid stirring up their supporters with inflammatory rhetoric.
The EU said on Wednesday that there was a lack of transparency in how the supreme court, the body that will ultimately have to ratify the results, was handling complaints over the organisation of the election.
Kabila is widely expected to be re-elected, but as only the second multiparty national elections since independence in 1960, Monday's vote is widely seen as an important test for the conflict-stricken nation’s frail democracy.