Heavy gunfire was heard Wednesday outside Guinea-Bissau's presidential palace just three days after the country's presidential and legislative elections, with both major candidates having claimed victory, an AFP journalist on the scene witnessed.

As shots rang out, people and vehicles fled from the area, the AFP journalist observed.

Official provisional vote results are expected Thursday in the tumultuous west African country, which has experienced four coups since independence, as well as multiple attempted coups.

Both the current president, Umaro Sissoco Embalo, and opposition candidate Fernando Dias have declared victory.

A passerby fleeing from the chaotic scene said"we're used to it in Bissau".

Embalo had been expected to win the election, which until Wednesday had passed off peacefully.

The vote had notably excluded the main opposition party PAIGC and its candidate Domingos Simoes Pereira from the ballot.

Pereira and PAIGC were struck from the final list of candidates and parties published in October by the Supreme Court, which said they had filed their official applications too late.

Pereira and Embalo are political arch-rivals: the last presidential election in 2019 was marked by a four-month post-election crisis as both men claimed victory.

The head of the Economic Community of West African States (ECOWAS) observation mission, Issifu Baba Braimah Kamara, had on Tuesday just praised the"peaceful conduct of the vote".

Guinea-Bissau is among the world's poorest countries and is also a hub for drug trafficking between Latin America and Europe, a trade facilitated by the country's long history of political instability.