An army general has been sworn in as Guinea-Bissau's new head of state a day after an apparent coup.

Gen Horta N'Tam becomes the transitional president for a period of one year. He took the oath on Thursday, in brief and muted proceedings in the army headquarters.

The military had already suspended the electoral process and blocked the release of the results of Sunday's presidential election which were expected on Thursday.

Some civil society groups in Guinea-Bissau have accused outgoing President Umaro Sissoco Embaló of masterminding a simulated coup against himself with the help of the military, saying it was a ruse to block election results from being released in case he loses.

This manoeuvre aims to prevent the publication of the electoral results scheduled for tomorrow, November 27, the civil society coalition Popular Front said in a statement on Wednesday.

The president has not responded to the allegations and has claimed he has survived multiple coup attempts during his time in office. Critics accuse him of fabricating crises to stifle dissent.

Situated between Senegal and Guinea, the West African nation is notorious for drug trafficking, with military influence persisting since its independence from Portugal in 1974. Guinea-Bissau has experienced at least nine coups or attempted coups in the last fifty years.

The latest coup saw military officers announce their control of the country, which followed reports that President Embaló was arrested. Gunfire was reported in the capital, Bissau, but specifics on casualties or involved parties remain unclear.

The officers stated they were thwarting a plot by unnamed politicians linked to a well-known drug baron and announced the closure of the country's borders along with a night-time curfew.

The delayed election results were anticipated on Thursday, with both Embaló and rival Fernando Dias claiming victories before the upheaval. Following the coup, sources indicated that crucial political figures, including Dias and the Interior Minister, were detained.

The African Union and Ecowas expressed deep concern over the coup announcement, emphasizing that Guinea-Bissau had been ready to release election results following a peaceful electoral process.

Portugal has urged for a return to constitutional order amidst the chaos as Guinea-Bissau attempts to stabilize.