A security officer has shot and killed an Ivory Coast based French journalist in front of police headquarters in the commercial capital Abidjan. The killing closely follows the arrest of a dozen opposition militants for what authorities called subversive activities.

Radio France Internationale (RFI) journalist Jean Hél?ne was shot in the back while waiting for the militants to be released from police detention on Tuesday night.

Mr. Hél?ne who first reported about the militants' disappearance earlier this week had been working with RFI since 1990. His colleagues say he had a passion for Africa. He was 50 years old.

French President Jacques Chirac called his killing an assassination. Ivorian President Laurent Gbagbo immediately promised a full investigation.

Mr. Gbagbo has denied being linked to death squads behind killings of opposition militants earlier this year.

Supporters of Mr. Gbagbo, including several militias, accuse foreign journalists of supporting rebels who control northern Ivory Coast since their failed coup last year. Rebels suspended their participation in a power-sharing government last month, accusing Mr. Gbagbo of keeping all power to himself and failing to implement a French-brokered peace accord.