Shortly after taking over the station, a soldier identified as Kelly Obiang announced the creation of a "National Restoration Council".
According to the BBC, army armoured vehicles and tanks were seen patrolling the streets of the capital, Libreville.
He has been out of the country in Morocco for more than two months where he went to seek medical treatment.
The 59-year-old president was hospitalised in October in Saudi Arabia after suffering a stroke.
Chhetri brace helps India hit Thailand for four at Asian Cup
We don't go into a match expecting to win 4-1 or 5-1. "Tomorrow morning, we train again", Constantine added. They are a very good side but we'll take it as another team standing in our way".
In his speech to mark the New Year, Bongo acknowledged health problems but said he was recovering.
Military officers have staged the coup in a bid to oust President Ali Bongo, who is now recovering from a stroke in Morocco.
He criticised "the high military hierarchy" for failing to defend "the best interest of the nation" by tolerating the president's lies about his health, referring to a New Year's speech made in Morocco in which he claimed he was well.
It is unclear if the earlier United States troop deployment is related to the coup, but President Donald Trump said Friday that USA military personnel had deployed to Gabon in response to possible violent demonstrations in the Democratic Republic of Congo after a presidential election there. For more on the story, we are joined on the LINE by Dr Ur Koumba, the President of Gabon Diaspra in SA. His family has ruled the oil-rich Central African nation for almost half a century.
He was narrowly re-elected in 2016 following a presidential poll marred by deadly violence and allegations of fraud.