Opposition candidates in Ivory Coast's election face charges of terrorism and up to life in prison for denouncing the vote and creating a rival government after President Alassane Ouattara's victory, a public prosecutor said on Friday.

The opposition boycotted the Oct. 31 ballot after Ouattara decided to run for a third term in a country that has a two-term limit.

When results showed Ouattara won with 94%, former president Henri Konan Bedie and ex-prime minister Pascal Affi N'Guessan said they did not recognise the vote and announced a transition government.

Ouattara, in power since 2010, says approval of a new constitution in 2016 restarted his mandate and allowed him to run again.

The standoff has raised the risk of long-term instability in Ivory Coast, the world's top cocoa producer and one of Africa's fastest growing economies.

The creation of a breakaway government was "intended to attack the authority of the state," lead prosecutor Richard Adou told reporters.

Twenty people were arrested outside Bedie's house on Nov. 3, when police in riot gear surrounded it. Nine were released but the other 11, including Bedie's second in command, Maurice Kakou Guikahue, are having their cases heard, a defence lawyer and a spokesman for Bedie's PDCI party told Reuters.

"Several other people who took part in this operation and who managed to escape are being actively sought," prosecutor Adou said.

Affi is one of those sought by police, Adou said. Bedie remains under effective house arrest, as he is unable to leave.

Bedie and Affi were not immediately reachable for comment.