Nigeriens are preparing for war against regional countries threatening to invade, three weeks after mutinous soldiers ousted the nation’s democratically elected president.

Residents in the capital, Niamey, are calling for the mass recruitment of volunteers to assist the army in the face of a growing threat by the West African regional bloc, ECOWAS, which says it will use military force if the junta doesn’t reinstate the deposed President Mohamed Bazoum. ECOWAS has activated a “standby force” to restore order in Niger after the junta ignored a deadline to reinstate and release Bazoum.

The initiative, spearhead by a group of locals in Niamey, aims to recruit tens of thousands of volunteers from across the country to register for the Volunteers for the Defense of Niger, to fight, assist with medical care, and provide technical and engineering logistics among other functions, in case the junta needs help, Amsarou Bako, one of the founders, told The Associated Press Tuesday.

“It’s an eventuality. We need to be ready whenever it happens,” he said. The recruitment drive will launch Saturday in Niamey as well as in cities where invasion forces might enter, such as near the borders with Nigeria and Benin, two countries, which have said they would participate in an intervention. Anyone over 18 can register and the list will be given to the junta to call upon people if needed, said Bako. The junta is not involved, but is aware of the initiative, he said.

Regional tensions are deepening as the standoff between Niger and ECOWAS shows no signs of defusing, despite signals from both sides that they are open to resolving the crisis peacefully. Last week the junta said it was open to dialogue with ECOWAS after rebuffing the bloc’s multiple efforts at talks, but shortly afterwards charged Bazoum with “high treason” and recalled its ambassador from neighboring Ivory Coast.

ECOWAS defense chiefs are expected to meet this week, for the first time since the bloc announced the deployment of the “standby” force. It’s unclear when or if the force will invade, but it would probably include several thousand troops and would have devastating consequences, say conflict experts.

“A military intervention with no end in sight risks triggering a regional war, with catastrophic consequences for the vast Sahel that is already plagued by insecurity, displacement and poverty,” said Mucahid Durmaz, senior analyst at Verisk Maplecroft, a global risk intelligence company.