By Media Coulibaly and Tim Cocks
ABIDJAN (Reuters) - Thousands of women marched through Abidjan on Tuesday calling for Laurent Gbagbo to step down, but witnesses said security forces shot four people dead near the scene of one march and another was broken up by armed youths.
Gunfire erupted in several other places where protests had taken place through the afternoon.
Meanwhile, the United Nations said some 450,000 people are now believed to have fled their homes as a result of the post-election crisis, which African leaders will discuss again on Wednesday at the African Union headquarters in Ethiopia.
Demonstrations were held in various parts of Ivory Coast's main city, a week after Gbagbo's forces shot dead seven women at an all-female march in Abobo, a neighborhood that has backed Alassane Ouattara, Gbagbo's rival for president.
Ever since Gbagbo rejected U.N.-certified results showing he lost a November poll to Ouattara, supporters of the latter have seen their attempts at protest met with violent repression.
Tuesday's marches initially appeared to go more peacefully, but were swiftly followed by outbreaks of gunfire.
In the downtown retail district of Treichville, witnesses said security forces fired on pro-Ouattara youths near a church, killing three young men and a 21-year-old woman.
"It was a sit in. We prayed, some Muslims some Christians, then we went to St Jean church. Then we heard firing outside," said Helene Sommet, a Ouattara activist who helped evacuate the dead from the scene and take the wounded to a clinic.
"We took in 14 wounded. I'm at the clinic right now," she said by telephone, adding she saw a truck with some of Gbagbo's elite Republican Security Company in the street.
There was no immediate comment from Gbagbo's military.
Fears that violence will interrupt supplies have pushed cocoa futures to 32-year highs. Cocoa exports have stopped because of European Union sanctions. Gbagbo officials announced a plan to nationalize the cocoa industry on Monday, raising fears he may seize their stocks [ID:nLDE72718Y].
In Port Bouet, near Abidjan's airport, witnesses said about 50 pro-Gbagbo youths armed with AK47 assault rifles and machetes turned up to disperse 200 women who tried to march there.
"They fired into the air to disperse the women. They had weapons to intimidate them, but they didn't hurt anyone," said Bernard Aurega, a Ouattara party member who saw the march.
The poll was meant to end a decade of instability and economic stagnation but resulted in deadlock and rising violence in Abidjan and the west of Ivory Coast has raised the prospects of another civil war in the world's top cocoa producer.
The U.N. has said at least 365 people have been killed during the crisis. Diplomats think the real toll is much higher.
U.N. aid agencies have revised the figure for people displaced to about 450,000, including some 90,000 who have fled into neighboring Liberia.
Ouattara's camp said he is due to attend a meeting at the AU headquarters in Ethiopia this week to discuss the crisis but pro-Gbagbo officials said he would send representatives.
Optimism for a diplomatic breakthrough is low.
Seven women were killed last Thursday when security forces opened fire on protesters in the northern pro-Ouattara suburb of Abobo, according to witnesses and military sources.
On Tuesday, the march there went off peacefully.
"Gbagbo, assassin! Gbagbo, power thief! Leave!" the women shouted and sang, some in traditional dress, others wearing T-shirts printed with Ouattara's face.
The only men with guns present were pro-Ouattara youths with AK47s and civilian clothes, who residents said were there to protect the march. But witnesses said almost as soon as the march petered out, machinegun fire rocked the neighborhood.
"It sounds like two groups fighting each other but I don't know," said resident Tiemoko Souala.
Another Abobo resident said they saw security forces move along the main street before the machinegun fire erupted.
Abobo is now largely controlled by pro-Ouattara insurgents calling themselves the "invisible commandos," after a week of gunbattles in which they pushed out police and military.
The U.N. and Western powers have warned Gbagbo he may face criminal investigation for crushing attempts at protest, although his military argues it has no choice because pro-Ouattara protesters are often armed and violent.
Dozens were killed during an attempted march on December 16, U.N. officials say, a protest followed by a wave of crackdowns on opposition areas in which scores were killed and kidnapped.
(Additional reporting by Loucoumane Coulibaly; Writing by Tim Cocks; Editing by David Lewis)