Guinea Bissau now has two presidents and two prime ministers after opposition leader Umaro Sissoco Embalo swore himself in as the new president.
The former governing party of Guinea-Bissau has also appointed an interim president and sworn in a prime minister.
The PAIGC lost last year’s election is currently in court to demand the results be overturned, although a ruling is yet to be made.
PAIGC has dominated politics since independence from Portugal in 1974. It has appointed parliamentary leader Cipriano Cassamá, as president.
Embalo who won the election according to the electoral commission said at his swearing in ceremony that “I swear on my honour to defend the constitution, to respect it and have it respected.”
He carried out the swearing in before a crowd of several hundred of his supporters at a hotel in the West African state’s capital, Bissau.
Outgoing president Jose Mario Vaz was at that event and placed the presidential sash over his shoulders.
Embalo, a 47-year-old former general and prime minister, won 53.55% of the votes in the December 29, 2019 runoff.
Domingos Simoes Pereira 56, from PAIGC, however won 46.45% of the votes in the run-off but has rejected the results.