Cameroon's government has warned that individuals or groups who attempt to announce unofficial results of Sunday's presidential vote will be subject to legal action.

"Official results of the presidential elections is the sole responsibility of the Constitutional Council. No one has the right to take the place of this jurisdictional authority," Cameroon's Minister of Territorial Administration Paul Atanga Nji told reporters.

"Any challenge of the poll verdict outside legal channels will not be tolerated," he added.

His comments came as the main opposition SDF's candidate, Joshua Osih, urged his supporters to attend vote counts at polling stations themselves and log their own findings on his party's mobile phone application called "Protect My Vote".