"If it exploded, it could have killed and destroyed anything within 5 kilometers or further, " Sallal said.

CNN: STORY HIGHLIGHTS

The plant employed 790 people, including 134 foreign workers, Sallal said Monday.

CNN: STORY HIGHLIGHTS

But regional analysts believe the operation was too sophisticated to have been planned so quickly, and Sallal said the hostage scheme had been hatched over months.

CNN: STORY HIGHLIGHTS

Sallal said the terrorist team that took the hostages had entered the country from northern Mali, where Malian and French authorities are battling Islamists who control the area.

CNN: STORY HIGHLIGHTS

The military tried to negotiate with the militants, but their demands to release militants held prisoner in Algeria were deemed unreasonable, leading to intervention by special forces troops backed by the Algerian Air Force, Sallal said.

CNN: STORY HIGHLIGHTS