Lawyers of Ivory Coast 's former first lady Simone Gbagbo have walked out the court in the capital Abidjan, claiming the latest trial against her was "biased". Gbagbo is already serving a 20-year sentence for "endangering state security" and is facing further charges on war crimes and crimes against humanity. This is for her alleged role during post-election violence in 2010.

Gbagbo's lawyers walked out after the judge refused to allow the defence to call politicians and officials as witnesses.

"We are suspending our participation until further notice. The process is biased, the court does not want a fair trial," Dohora Blede, one of the lawyers defending Gbagbo, was quoted by AFP news agency as saying.

"We noticed that our witnesses were not present – we have asked for a delay of four days to see these people, who are indispensable for demonstrating the truth."

The prosecution rejected the choice of witnesses and the court susbequently ruled the defence did not have the authority to call the witnesses.

"We are stunned – these people include some who have gone to the International Criminal Court (ICC) thousands of miles away. We're asking them simply to come here by car. We can't explain it,"Blede continued.

In 2010, former Ivory Coast's President Laurent Gbagbo contested the result of presidential election that saw Alassane Ouattara emerging as winner and refused to step down.

Violence erupted in the aftermath of the election causing the death of at least 3,000 people. More than 150 women were raped or gang-raped, people faced summary executions and villages were burned down during the civil unrest.

Gbagbo was forcibly removed from his office in April 2011. He is standing trial at the International Criminal Court (ICC) on four counts of war crimes and crimes against humanity for the post-election violence sparked in 2010.

His wife was sentenced to 20 years in March 2015. The couple both denied the charges.

In May, the country's supreme court rejected the former first lady's appeal against her prison sentence.

Ivory Coast's 2020 election

Meanwhile, supporters of proposed constitutional amendments in Ivory Coast have started a campaign ahead of a referendum on 30 October. The "Yes" camp campaign is led by the government and aims to gain support for the new draft document before citizens head to the polls to decide whether they want to modify the current constitution.

The proposed changes scrap, among other things, the requirement that both parents of a presidential candidate must be native-born Ivorians and a clause that sets 75 as age limit to be able to run for president.

The draft document has fuelled speculations that 74-year-old Ouattara, whose father is from Burkina Faso, is seeking a third term in 2020, something he denies. Critics of the proposed amendments have claimed they are anti-democratic.