A protest outside the Congolese Embassy in Ottawa Friday has calmed down after police clashed briefly with demonstrators.

Ottawa police used pepper spray on demonstrators outside the embassy on Range Road after a number of protesters started shaking the fences between them.

Ottawa police have confirmed they have made one arrest in connection with the conflict.

Most of the Congolese protesters held back from the confrontation and were peacefully protesting.

At its height, the protest had swelled to hundreds of people. But by 5 p.m. their numbers had dwindled to about 50 people, who were outnumbered by police.

The demonstrators, who came from various cities, took to the streets in Ottawa Friday over what they call a fraudulent election in their home country.

The protest began at Parliament Hill and went to the British High Commission and the U.S. Embassy before moving on towards the Congolese Embassy.

The protest was peaceful throughout but got rough once protesters arrived outside the embassy. The protest against Congo's president stalled traffic throughout downtown Ottawa on Friday. (CBC)

The group, which included people bused in from Toronto, Montreal and Sherbrooke, Que., are supporters of Congo opposition candidate Étienne Tshisekedi, who lost a contested election to incumbent president Joseph Kabila last week.

Election called a fraud

Protesters have accused Kabila of voter fraud and intimidation in his victory, but international observers have stopped short, saying instead the vote was flawed.

Raissa Nkube said the protesters are calling on the Canadian government to end its support for Kabila.

"He's been in power for 10 years. He's only destroyed Congo. Why is Canada supporting him? We want it to stop," she said.

Rideau Street was closed between Sussex Drive and Charlotte Street because of the protest and downtown traffic was slow as the demonstration went on the move.

Range Road was also closed between Laurier and Mann avenues.