Reports from Lagos in Nigeria say transport fares in Nigeria have been increased four-fold -- just one day after fuel distributors in the country announced they were doubling the price of petrol.

Many bus and taxi operators, who were caught unawares by the new fuel prices, quickly raised their fares.

Commuters who couldn't afford the increased prices were stranded at bus stops.

Earlier the Nigerian military government said that the market would in future determine fuel prices, which had been fixed by the authorities at the same level for the last four years.

Correspondents say industry analysts believe the move is a sign the government will soon deregulate the oil market.