A police member casts his vote ahead of the presidential election at the National Election Commission headquarter in Bissau. Photo: REUTERS/ Christophe Van Der Perre.

BISSAU — Guinea-Bissau is holding a presidential election Sunday against a backdrop of political tension and unrest on the streets of the impoverished West African country.

Twelve candidates are running for head of state, including the incumbent, Jose Mario Vaz, who has been in power since 2014.

He is the first democratically elected president to complete a full term in a country that has seen a number of coups and attempted coups. Vaz is also running against two of the prime ministers he has fired during his five years in office.

Guinea-Bissau, a former Portuguese colony of around 1.5 million people, is one of the world’s poorest countries. It has been plagued by political instability, poverty, corruption and drug-trafficking, especially cocaine. The most recent military coup was in 2012.

The candidates' agendas include promises to fight the cocaine smuggling that has used Guinea-Bissau as a staging post between Latin America and Europe, prompting the United Nations to describe the country as a “narco state.”

Candidates have also pledged to ensure political and governmental stability, create an effective public health and education system, and make a diplomatic push to restore the country’s international image.

The nearly 800,000 registered voters are hoping Sunday’s ballot can foster change after years of political turmoil.

If no candidate captures more than 50% of Sunday’s vote, a runoff ballot is to be held between the two top candidates on Dec. 29.

Last month, one person died and three others were injured when police used tear gas to break up an unauthorized street march organized by opposition parties.

Barely three weeks before the election, Vaz, the incumbent, fired the prime minister, Aristides Gomes, and his Cabinet, elected last March, in a power struggle.

Vaz replaced Gomes with Faustino Fudut Imbali, but Gomes refused to leave office, saying the order to leave was invalid because Vaz’s term legally ended on June 23.

The attempt to remove Gomes prompted an international outcry and appeals for stability from the United Nations, the European Union and the 15-nation Economic Community of West African States, with observers warning of a threat of civil war.

The West African bloc, ECOWAS, called the move by the president illegal and threatened sanctions. Imbali then resigned.

Vaz’s strongest rival is former prime minister Domingos Simoes Pereira, who Vaz fired in 2015. That move led to years of tension between the head of state and parliament.

Vaz again refused to name Pereira as prime minister in June this year, after March legislative elections. Vaz has vowed he will comply with the result of Sunday’s ballot.

ECOWAS stationed 600 troops in Guinea-Bissau in 2012 to discourage armed uprisings. It wanted to increase the contingent to 2,000 this month for the election, but the country’s powerful military disallowed it.

Guinea-Bissau became independent from Portugal in 1974, but it has struggled to get any momentum in its economic growth. Most people farm for a living.

After the turn of the century, Latin American drug gangs used the country as a depot for the trafficking of cocaine into Europe by air and sea. The gangs became so influential that they unsettled local politics.

The drug trade has become less obvious since international law enforcement bodies joined a crackdown and made large seizures.

Associated Press