The first major trial opened Tuesday of soldiers loyal to ousted Ivory Coast president Laurent Gbagbo in connection with crimes during the country's post-election crisis in 2010-2011.

General Brunot Dogbo Ble, a pillar of Gbagbo's security apparatus, and four other soldiers appeared in civilian clothes before a crowded court in the economic capital Abidjan to answer for their actions during the former leader's standoff with current President Alassane Ouattara, which claimed some 3,000 lives.

The trial, which has been organised by military prosecutors and is being heard by a panel of both military and civilian judges, opened several hours behind schedule under tight security at the main courthouse in the Plateau district.

Speaking for the defence, lawyer Raoul Gohi-Bi denounced the trial as "botched" and asked for it to be thrown out, saying the matter should have been handled exclusively under military jurisdiction.

The prosecution said the case was being handled in accordance with the law.

The case opened several hours behind schedule, and presiding judge Mathurin Kangah Penon adjourned it until Wednesday after about an hour of opening proceedings.

Dogbo Ble and his co-defendants are charged with crimes including murder, rape, kidnapping, theft, arbitrary detention, embezzlement and creating militia forces.

A team of 17 lawyers is representing the five defendants.

Military prosecutor Ange Kessi said the trial marked the start of a series in which about 40 soldiers are expected to appear in court.

As head of the feared Republican Guard under Gbagbo, Dogbo Ble was a strongman of the regime before it fell on April 11, 2011, after four months of crisis during which Gbagbo refused to admit defeat at the polls to Ouattara.

The senior officer was arrested in Abidjan on April 15 and has been detained ever since. He faces several charges under military justice, as well as a civil charge of genocide.

Kessi announced on Monday that Dogbo Ble and two other officers were also accused of complicity in the murder of a former junta chief, Robert Guei, who was killed on September 19, 2002, the day of a foiled coup against Gbagbo, which was followed by the fall of the north of the country into rebel hands.

The opening of the trial comes amid a climate of tension after a series of deadly attacks against soldiers in August, when the army lost about 10 men.

The authorities blamed the attacks on Gbagbo loyalists, but his supporters deny any involvement.

The authorities arrested key opposition figures in the wake of the attacks.

Laurent Akoun, General Secretary of Gbagbo's Ivorian Popular Front (FPI), has been sentenced to six months in prison for disturbing the peace, and the ex-president's former spokesman, Justin Kone Katinan, has been arrested in Ghana, where he faces murder charges and extradition proceedings.

New attacks claimed seven lives in Abidjan and on the border with Ghana on September 20-21.

The opposition frequently accuses Ouattara's government of carrying out "victor's justice", while international organisations have also expressed misgivings. None of Ouattara's supporters have been arrested for crimes committed during the post-electoral crisis.

According to a report by a commission set up by the authorities, pro-Ouattara forces were responsible for the deaths of more than 700 people. Pro-Gbagbo forces are accused of killing twice as many.

Suspected by the International Criminal Court of an indirect role in crimes against humanity, Gbagbo has been detained pending trial in The Hague since the end of 2011.

About a score of leading figures from the ousted regime, including Gbagbo's wife Simone, and dozens of others who backed them, are currently being held in Ivory Coast.