The official campaign period has been launched in Senegal for the presidential elections due in three weeks' time.

But already there have been allegations of fraud.

An opposition alliance grouping about twenty parties has accused the Socialists, who have governed the country since independence forty years ago, of preparing to massage the results through the use of doctored voting cards.

The alliance, known by its initials FRTE, have also charged the interior minister, General Lamine Cisse, with tampering with the electoral list.

President Abdou Diouf has said he will do his utmost to ensure there are no abuses.

He faces seven challengers.

From the newsroom of the BBC World Service