Supporters of the National Democratic Congress held demonstrations across Ghana on Sunday calling for the results of the December 7 vote to be overturned.
Dressed in red, they sang their party's slogans while police kept an eye on them.
Ghana's election commission declared president Nana Akufo-Addo winner of the election with nearly 51.6% of the vote.
But the result was quickly rejected by the loser John Mahama who accused the ruling party and president Akufo-Addo of engaging in fraud to retain power.
The election was the third time the two men were facing off in a vote. Akufo-Addo has been declared winner on two occassions.
The ruling party has insisted that the vote was free and fair.
The march was mostly peaceful. But some young men burned car tyres prompting a brief confrontation with security forces.
Army soldiers were called in to reinforce the police.
Ghana has enjoyed relative political stability since the return of multi-party rule in the 1990's.
Peter Adattor reports