Tensions continue to rise in the West African nation of Niger, after military leaders who staged a coup rejected a regional bloc's request to reinstate the president by a Sunday deadline.

The coup leaders announced on Sunday that they closed the country's airspace, citing the possibility of military intervention by the Economic Community of West African States, or ECOWAS.

ECOWAS has condemned the July 26 coup that ousted pro-Western President Mohamed Bazoum, and warned that its members would use force if the coup leaders fail to reinstate him by Sunday.

The Associated Press reports that the leaders have contacted Russian private military firm Wagner Group in neighboring Mali and sought its support.

Mali and another neighboring country Burkina Faso, both of which are members of ECOWAS, oppose the block's military intervention. The two countries are run by military leaders who grabbed power in coups.