"Yes, there is a 48-hour delay," Laurent Ndaye, a spokesman for Congo's national election commission, told Reuters. "We have not received all the official tallies from polling stations, that is the reason."

Partial preliminary results from the November 28 vote, representing 70 percent of the ballots cast, give President Joseph Kabila a 10-point lead over Etienne Tshisekedi.

Kabila has 46% of the vote, with Tshisekedi trailing with 36% with two-thirds of the ballots counted.
The opposition has said it will reject the outcome.

There are fears rising that a rejection of the results will unleash bloodshed. Tshisekedi enjoys broad support in Kinshasa, a city of 10 million people, as well as the two southern Kasai provinces, which have seen security beefed up in recent days.

There was a heavy security presence on the streets of the capital on Tuesday, and some residents piled into boats to cross the Congo River into neighbouring Congo Republic, fearing renewed violence after the results.