A group of senior Gabonese military officers appeared on national television in the early hours of Wednesday and said they had taken power, after the state election body announced President Ali Bongo had won a third term.

Appearing on television channel Gabon 24, the officers said they represented all security and defense forces in the Central African nation. They said the election results were canceled, all borders closed until further notice and state institutions dissolved.

Loud sounds of gunfire could be heard in the capital Libreville, a Reuters reporter said, after the television appearance.

There was no immediate comment from the government of the OPEC-member nation.

"In the name of the Gabonese people ... we have decided to defend the peace by putting an end to the current regime," the officers said.

If successful, the coup would represent the eighth in West and Central Africa since 2020. Coups in Mali, Guinea, Burkina Faso, Chad and Niger have undermined democratic progress in recent years.

Last month, the military snatched power in Niger, sending shockwaves across the Sahel and sucking in global powers with strategic interests at stake.

The announcement came just hours after the Gabonese Election Centre (CGE) said on Wednesday that Bongo had won in the presidential election with 64.27% of the vote, after a delay-plagued general election that the opposition has denounced as fraudulent.

Announcing the result in the early hours, CGE head Michel Stephane Bonda said Bongo's main challenger, Albert Ondo Ossa, had come in second place with 30.77%. Bongo's team have rejected Ondo Ossa's allegations of electoral irregularities.

Tensions are running high amid fears of unrest after Saturday's presidential, parliamentary, and legislative vote, which saw Bongo seeking to extend his family's 56-year grip on power while the opposition pushed for change in the oil-rich but poverty-stricken Central African nation.

A lack of international observers, the suspension of some foreign broadcasts, and the authorities' decision to cut internet service and impose a nighttime curfew nationwide after the poll has raised concerns about the transparency of the electoral process.

Bongo, 64, who succeeded his father Omar as president in 2009, had contested against 18 challengers, six of whom backed a joint nominee, former minister and university professor Albert Ondo Ossa, in an effort to narrow the race.

In 2016, the parliament building was torched when violent street protests erupted against Bongo's contested re-election for his second term. The government shut down internet access for several days at the time.

This is a breaking story. More to come