LIBREVILLE (Reuters) - Opposition supporters in Gabon rampaged through the streets of the capital, burning cars and setting fire to the embassy of Benin, following the death on Sunday of a senior opposition leader, according to a Reuters witness.
Andre Mba Obame, once one of Gabon's leading opposition figures, died in neighbouring Cameroon, his National Union political party said.
Mba Obame served as an adviser to longtime President Omar Bongo, eventually rising to the post of minister of the interior. However, he broke with the ruling party to run for the presidency as an independent following Bongo's death in 2009.
Though official results handed victory to the late leader's son, Ali Bongo, Mba Obame declared himself the winner, leading the authorities to accuse him of treason.
No cause of death was given in the statement from the National Union, which Mba Obame joined not long after the 2009 election.
A Reuters witness who followed a group of supporters as they burned government service cars on a rampage through the streets of the capital, Libreville, before arriving at Benin's embassy, said many accused the government of poisoning Mba Obame.
"The embassy of Benin was completely burned," said the witness.
There was no immediate response from the Gabonese authorities.
"This is an immense loss for the National Union, the Gabonese opposition, and for our country Gabon," the party's statement said, adding that Mba Obame had died around noon on Sunday in Cameroon's capital, Yaounde. He was 57 years old.
Mba Obame served as executive secretary of the National Union, though the government outlawed the party two years after the disputed polls.
The ban was lifted in February, however, clearing the way for the party to put forward a candidate against President Bongo in next year's election.
Mba Obame has been frequently absent from the central African oil-producing nation for health reasons since 2009 and it has not been clear who would lead the National Union.
Former African Union head Jean Ping is currently the main opposition figure in the oil-producing state although recent torture charges brought against him have clouded his political future.
Bongo has faced mounting criticism in recent months over a range of grievances and trade union disputes, leading to violent demonstrations in December in which one protester was killed.
(Writing by Joe Bavier, editing by David Evans and Matthew Lewis)