An army statement said the raids took place last week in the Tagueye locality, near Niger's western border with Burkina Faso. It said 13 insurgents were killed and one arrested.
"Previously under the control of armed terrorist groups, these sites have been dismantled and systematically rendered inoperative," said the army statement released over the weekend.
The raids "aimed at drying up the sources of financing for terrorist activities", it said.
Like Sahel neighbours Mali and Burkina Faso, Niger is battling an insurgency by jihadist groups linked to Al Qaeda and Islamic State that have killed thousands and taken control of villages in its western border and the south.
The military-ruled government expelled French forces, turning instead to Russia to help fight the insurgents.
Ryan Cummings, director of the Africa-focused intelligence firm Signal Risk, said the raids may have temporarily disrupted illicit gold mining, but cutting off insurgents' financing required stronger efforts.
"The minute state forces depart areas and mining sites with militant presence, the same actors can return to these deposits and restart operations," Cummings said.
The insurgency in Niger has further battered the economy in Niger, where around 4.5 million people, or 17% of the population, required aid in 2024, according to the United Nations.
In May, eight staff of privately-owned Nguvu Mining, which operates the Samira Hill gold mine southwest of the capital Niamey, were killed when the military-escorted bus they were travelling in ran over an IED, a company executive told Reuters.
--Reuters--