There was violence on the streets of Gabon's capital Libreville over a disputed election result.
Incumbent president Ali Bongo has just been given a second seven-year term after being declared the winner by a margin of under 6,000 votes.
Opposition leader Jean Ping won six out of nine provinces, but his supporters say the result in Mr Bongo's home province is suspect.
Voter turnout there was put at a massive 99.93 per cent, and 95 per cent of the votes were allegedly for the president.
Opposition politician Paul Marie Gonjout says those kinds of percentages are fanciful.
"Where in this world you can see a country with a level of participation of 100 per cent? Where? Tell me."
In a televised address, President Bongo has insisted the election was free and fair and says democracy is important to him.
"This project is close to my heart, and this is what has led me to scrupulously respect the electoral code all the way and to not intervene at any time, nor to seek to influence those who were in charge of achieving this electoral process, which I intended to be open and transparent."
President Bongo took office in 2009, succeeding his father Omar Bongo, who came to power in 1967.
Jean Ping, the opposition leader, has gone into hiding but has been on the phone to various media outlets, including the BBC.
He says a helicopter from Ali Bongo's presidential guard bombed opposition headquarters and killed two people.
"Well, the situation in Libreville at the moment is very, very, very bad, because the presidential guard, last night by helicopter, they have attacked our headquarters. They arrested almost everybody."
President Bongo's office has accused the opposition of planning coordinated attacks on symbols of state, forcing the security forces to encircle opposition headquarters.
In France, Gabon's former colonial ruler, Gabonese nationals living in Paris who support Jean Ping have gathered to protest against the election result.
"I am here because I don't agree and I refuse that some Gabonese be sacrificed for the power of a few, for the benefit of a few. Today, when you're wise, you understand the message of the people."
French prime minister Manuel Valls has added his voice to calls by the United States and the European Union for calm.
"Good sense, which means making sure the poll is transparent, respecting electoral law and calming the tensions -- the President has spoken about it -- must win out against the temptation to resort to violence."
