REPUBLIKA.CO.ID, ABIJAN -- Up to 1,000 supporters of Ivorian ex-president Laurent Gbagbo are in prison where several are subjected to torture, the head of the country's former ruling party said on Thursday.

"After our investigations in jails and with family members, we count 700 prisoners," Affi N'Guessan, the president of the opposition Ivorian Popular Front told journalists, calling this "an approximate figure".

"We are convinced that there are up to 1,000 of our peers who live in this hell," he said. "Some of them are tortured."

Fifty prisoners detained during Ivory Coast's post-election crisis between 2010 and 2011 were released in May, a gesture interpreted as a sign of appeasement for followers of Gbagbo.

The government has said the release of an additional 100 detainees is "in progress".

A list of 719 prisoners presented by the Ivorian Popular Front includes more than 200 military personnel and individuals whose cases are yet to reach court, the party said.

At a press conference on Thursday, justice minister Gnema Coulibaly said he condemned acts of torture committed in the country's prisons.

Gbagbo ruled the Ivory Coast from 2000 until he was arrested at his presidential bunker in Abidjan in 2011.

He is currently in custody awaiting trial at the International Criminal Court on charges of crimes against humanity.