Niger arrested senior military officers planning to use the nation’s air force to topple the government ahead of February’s presidential election, President Mahamadou Issoufou said.

The officers had been plotting for weeks, Issoufou, 63, said Thursday in a speech broadcast on state television. The president is seeking re-election next year, with the first round of voting scheduled for Feb. 21. Niger is the world’s fourth- largest producer of uranium, the material used to fuel nuclear power plants, and pumps crude oil.

“The government has thwarted an unfortunate attempt at destabilization,” Issoufou said. “The objective was to overthrow a democratically elected regime. They planned to use the firepower of air force assets.”

Authorities arrested opposition leader Hama Amadou last month when he returned to the country after more than a year in self-imposed exile in France. He had been prime minister twice and said in September he intends to vie in the presidential election.

One of the poorest nations in Africa, Niger’s government has been struggling with slumping prices for commodities and a growing threat from Islamist militant group Boko Haram. Niger is part of a military coalition with Chad, Nigeria and Cameroon fighting Boko Haram, which has started attacking towns outside its base in Nigeria.

Areva SA, the world’s largest builder of nuclear reactors, operates a uranium mine in Niger. Issoufou, who had previously served as prime minister in the 1990s, was elected president in 2011.

First Published December 18, 2015, 7:23 a.m.