The Independent Electoral Commission in South Africa says its first voter registration drive has been a success, despite early indications that only between a quarter and a half of all eligible voters registered in the five northern provinces.

Opposition parties say that if less than half of the electorate is able to vote in elections due next year, any result will lack credibility.

Voter surveys suggest that the low turnout to register will favour the governing African National Congress, as its committed supporters are likely to be prevalent among those who registered.

The BBC correspondant in Johannesburg says that the pressure is now on the government and the commission to extend the registration process.