The election authorities in the Democratic Republic of Congo say they are set to announce officially the results of the national elections.
DR Congo's people had not had such elections since 1960
Security forces and foreign peacekeepers are on alert in case of unrest over the outcome of the July 30 vote for a president and parliament.
They were the first nationwide elections since independence in 1960.
Partial results show President Joseph Kabila just below the 50% he needs to avoid a run-off with his nearest rival.
Angola has confirmed sending extra troops to the border but called it a routine security procedure.
Three TV stations have been suspended for 24 hours after broadcasting images that could incite violence.
One is a state channel and another is owned by Mr Kabila's closest challenger - his vice-president and former rebel Jean-Pierre Bemba.
According to the electoral commission site, with the votes of some 13m of the 25m registered voters votes counted, Joseph Kabila has 48.4% and Mr Bemba 16.2%.
So far the elections have gone remarkably smoothly bearing in mind Congo has been in turmoil for decades, says BBC Africa analyst David Bamford.
DR Congolese organisers and their UN backers all have their fingers crossed that the process does not falter at this vital hurdle, he adds.
Our correspondent says unrest could come in two forms: from the supporters of presidential and parliamentary candidates who do not like the official outcome ands from supporters of the mainstream opposition UPDS, which has boycotted the elections altogether.
Many of the presidential candidates have complained of "massive irregularities" in the vote count.
France's foreign ministry called on all political parties "to show responsibility and not to fan the flames of tension".
Deputy spokesman Denis Simonneau also praised the presence of the 1,000-strong European Union and 17,000 United Nations troops in the DR Congo as "critical to allow the electoral process a peaceful conclusion".
The polls are meant to put an end to a transition process established after five years of war that ended in 2003.