President Bongo, 64, is under house arrest, surrounded by his family and doctors, military officers have said on national TV in the last few minutes.

Soldiers also said one of the leader's sons was under arrest for "treason".

They added that they had put forward the head of the presidential guard as the leader of the transition.

In an earlier TV appearance, soldiers said they were cancelling the result of the election which saw President Bongo - whose family has been in power for more than half a century.

Former colonial power France has voiced its concern over the situation, as have China and Russia - countries which both have modern-day influence in central and west Africa.

If confirmed, this would be the eighth coup in former French colonies in Africa in the past three years.