Cameroon has declared a public holiday to mark the inauguration of President Paul Biya, the BBC’s Mayeni Jones reports.
The 85-year-old secured a seventh term in office after winning 71% of the vote in the 7 October election.
Opposition parties, however, contested the win saying the election was marred by fraud but their petitions were dismissed.
Mr Biya has been in power since 1982.
His inauguration comes a day after gunmen seized at least 79 students and three others, including the principal in Bamenda, the capital of the restive North-West region.
No group has said it carried out the kidnapping at Bamenda’s Presbyterian Secondary School, which has pupils aged between 10 and 14.
The government has blamed Ambazonia separatists who want to create an independent state in the English-speaking region.
A video of some of the children, believed to have been filmed by one of the kidnappers, is being shared on social media.
Cameroonian Journalist Peter Tah told the BBC’s Newsday radio programme that parents of the children at the same school are now reluctant to send their children to school.