"This Thursday, June 19, a cowardly and barbaric attack was carried out against (the town of) Banibangou by a horde of several hundred mercenaries aboard eight vehicles and more than 200 motorbikes," the ministry said in a statement read out on state television, adding that 34 soldiers were killed and 14 wounded.

The ministry said that its forces killed "dozens of terrorists" in the battle.

The ministry said it had sent reinforcements to the town and was conducting search operations by land and air to try to find the attackers.

Both Niger and Mali, who are run by military juntas, have struggled to contain jihadist violence, which has intensified in recent weeks.

Banibangou lies close to the three-way border between Niger, Mali and Burkina Faso, an area infested with jihadist groups aligned with Al Qaeda and Islamic State.

Niger is also battling jihadists linked to Boko Haram and its offshoot Islamic State West Africa Province in its southeast, which borders Lake Chad and Nigeria.

Niger has been ruled by a military junta for the last two years, during which time it expelled French and US forces that had been heavily involved in the fight against jihadists.