Former Ivory Coast President Laurent Gbagbo is be tried at the International Criminal Court on charges of crimes against humanity during post-election violence in which around 3,000 people were killed, judges said on Thursday.

Gbagbo is accused of plunging his country into civil war rather than relinquish his grip on power after losing a presidential run-off vote in 2010.

In the 131-page ruling, judges found there were "substantial grounds to believe" Gbagbo was criminally responsible for the crimes committed during the violence, singling out supporters of his political rival Alassane Ouattara for "systematic attack".

Prosecutors say he devised a plan with co-conspirators including his wife Simone, who remains under house arrest in Ivory Coast, and youth leader Charles Ble Goude, currently in ICC custody, to stoke the violence and benefit from it.

"It's the first victory for the victims of the post-election crisis," said Issiaka Diaby, who heads a collective of victims of the violence. "From today, people will know you can no longer kill and burn people with impunity."

Lawyers for Gbagbo could not be immediately reached for comment and it was unclear whether they planned to appeal the judges' decision that prosecutors had submitted enough evidence to justify pursuing the case.

"The Ivorian Popular Front expresses its astonishment and bitterness faced with a decision that contributes nothing to national reconciliation," Gbagbo's political party said in a statement published late on Thursday.

Supporters of Gbagbo and Ble Goude have accused Ouattara, now president, of using the court as a political tool to get rid of his political enemies. They have criticised prosecutors for bringing cases only against Gbagbo and his allies.

"Obviously the decision that was taken was the one we were hoping for, because the evidence was there," Ivorian government spokesman Bruno Kone said. "I think it is a good thing for the victims."

The decision to commit Gbagbo for trial is a success for the court's prosecutors, who have been criticised for building weak cases that have been thrown out before reaching trial.

The court, set up a decade ago to try those accused of the worst international crimes, has handed down just three verdicts in its first decade.

New York-based Human Rights Watch welcomed the decision to try Gbagbo, which it said would "remind those in positions of power that they are not immune from justice".

Gbagbo has been in custody since 2011, when Ouattara handed him over to the Hague-based court. Gbagbo could face a maximum prison term of life imprisonment if convicted. No trial date has yet been set.