|Election is seen as a litmus of test for Cote d'Ivoire following the 2002-3 war that split the country [EPA]
Voters in the West African nation of Cote d'Iivoire are casting their ballots in a presidential election aimed at ending a decade of political and economic crisis.
Laurent Gbagbo, the incumbent president, faces Alassane Ouattara, a former prime minister and senior IMF official, in Sunday's tight race that has triggered violence and rekindled simmering tensions in the world's top cocoa grower, divided by a 2002-2003 civil war.
At least three people have been killed in the capital Abidjan when police opened fire on a crowd, despite efforts to maintain calm before Sunday's presidential run-off.
Phillipe Mangou, the army chief of staff, said on Saturday that a night-time curfew would take effect from Saturday through to the end of Wednesday, citing scuffles between youths wielding sticks, machetes and guns in and around Abidjan.
After a peaceful first round, Gbagbo is squaring off against Ouattara, his rival from the rebel-controlled north, in what is expected to be a close second round.
Gbagbo won 38 per cent of the vote in the first round and Ouattara trailed with 32 per cent. However, Ouattara has secured the support of Hennri Konan Bedie, the third place candidate who got 25 per cent of the vote in the last poll.
Ouattara said on Saturday that the curfew would be illegal and unconstitutional, adding that the move would only make sense if there is trouble after the election.
He said that he would not respect the curfew because it would open the door to electoral fraud.
Many fear large-scale violence if the result is disputed as supporters on both sides have a history of taking to the streets.
"The stakes are very high. The first round was very good. [But] we have seen some radicalisation," Gilles Yabi, an independent political analyst, said.
"I'm afraid we can expect some degree of violence."
Yves Doumbia, a spokesman for the mayor in Abidjan's Abobo neighbourhood, said crowds had gathered and become unmanageable when the latest violence broke out.
"The police used teargas and fired live rounds at a crowd, killing three and wounding seven," Doumbia said.
It was not immediately clear why the crowds had gathered but Abobo is regarded as a pro-Ouattara district and opposition neighbourhoods have criticised the curfew as a ploy to allow vote-rigging to take place.
"It is our duty to sound the alarm and put security measures in place to save lives," Mangou said. "We don't want any more deaths, we don't want any more injuries."
Ouattara and Gbagbo were polite with each other in a televised debate but divisive rhetoric by the two candidates and clashes between supporters this week have soured the mood.
"As you see, the style of the head-to-head on the television that was appreciated by everyone did not have an effect on the behaviour of the militants. On the contrary, we have seen a resurgence in violence," Mangou said.
He said there had been "some deaths" overnight, listing at least two, and many people had been wounded, including 10 seriously in one battle. Two others were killed in clashes on Thursday, the interior ministry said in a statement on Friday.
The curfew runs from 10 pm (2200 GMT) to 6am on Saturday and Sunday, and from 7pm to 6am on Monday, Tuesday and Wednesday.
"The curfew will not have any impact on the transparency of the election," Mangou said.