The demonstrators filmed themselves invading the empty offices in the French capital's chic 16th district around 7:00 pm (1800 GMT) on Saturday, broadcasting the protest live on Facebook.
Police forced them out of the building two hours later and onto the street, where they continued their protest outside the embassy.
A local resident who witnessed the protest told AFP the protesters had “jumped over the railings and smashed the door open”.
“They are taking Cameroonians for idiots,” protester Daniel Essissima said in the Facebook video.
“They cannot bring people to rock-bottom like this. In the anglophone regions the army is killing people; in Douala, they are firing with real bullets,” he charged.
At least three people were shot in Cameroon's southern city of Douala on Saturday at a protest by the opposition Members of the Rebirth of Cameroon (MRC), according to party activists.
Communications Minister Rene Emmanuel Sadi insisted that “no real bullets were fired” at the protest.
The Cameroon government said on Sunday that 117 people had been arrested Saturday for breach of order at opposition protests in the capital Yaounde as well as the cities of Bafoussam and Mbouda.
MRC leader Maurice Kamto continues to claim he was the rightful winner of last October's presidential election.
The 85-year-old Biya, in power for 36 years, won a seventh consecutive term in an election blasted by the MRC as an “electoral hold-up”.
Cameroon has been shaken over the past year by an armed revolt among fringe separatists in anglophone regions demanding independence from the majority French-speaking country. Armed men have carried out a wave of kidnappings of officials, soldiers and police officers as well as civilians in the anglophone Southwest and Northwest regions.
Armed separatists have been clashing with the Cameroonian military almost daily in the country's equatorial forest.