After observing "irresponsible, unpredictable governance resulting in a continuing deterioration in social cohesion that risks leading the country into chaos... we have decided to defend peace by putting an end to the current regime," the media quoted one of the soldiers as saying.
The soldier was speaking on behalf of the "Committee for the Transition and Restoration of Institutions," the report said.
The journalists also reported that gunfire was heard in Gabon's capital, Libreville.
Earlier on Wednesday, Ali Bongo Ondimba, the president of Gabon, was reelected as the country's head for the next term after securing 64.2% of votes.
The president, 64, was first elected the head of state in 2009 after the death of his father, Omar Bongo Ondimba, who served as the country's ruler for over 40 years.
The borders of Gabon will remain closed until further notice, media added.