Gambian President Yahya Jammeh has declared a 90-day state of emergency, a day before his tenure ends.
Regional leaders have unsuccessfully tried to persuade him to hand over power to Adama Barrow, who won December presidential elections.
The move came after Nigeria deployed a warship to put further pressure on Mr. Jammeh.
Regional bloc ECOWAS has prepared a force but maintains that military intervention would be a last resort.
In his televised announcement, Mr. jammeh said "any acts of disobedience to the laws in the Gambia, incitement of violence and acts intended to disturb public order and peace" are banned under the state of emergency.