Fourteen troops were killed following an ambush by “heavily-armed terrorists” in the western Niger region of Tillaberi, the interior ministry said Thursday.

“After a fierce battle … seven police and seven national guards were killed,” the ministry said in a statement. “A guard has been listed as missing … the enemy suffered many losses.”

The attack took place as the troops were traveling with a team of civil servants who planned to carry out voter registration in the district of Sanam ahead of next year’s presidential and legislative elections. The ministry confirmed that the team had been “returned to Sanam safe and sound.”

Niger, a poor, landlocked country in West Africa, has been fighting off a jihadist insurgency from Boko Haram on its southeastern border with Nigeria and Islamic State allied militants in the west near Mali. There are also other armed groups operating in the Sahel, a climatic region that extends south of the Sahara from the Atlantic to the Red Sea, some of whom have sworn allegiance to ISIL or al-Qaeda.

Dozens of people have been killed in terrorist attacks this month alone. On December 10, 71 soldiers were killed in Niger’s Tillaberi region after jihadists attacked a military camp with shelling and mortars, in the single worst terrorist attack since the insurgency began.

Nigerien forces are backed by the United States, who this year provided additional funding to increase security for troops amid threats of violent ambushes. Last year, Washington also expanded its military presence across Niger and other neighboring countries in support of the “G5 Sahel” counter-terrorism force by led by France and containing 5,000 troops from five Chad, Niger, Burkina Faso, Mali, and Mauritania.

Earlier this year, the Nigerien government approved the use of armed drones over the country’s airspace, meaning U.S. military forces can target militants and protect their own forces. Drones were previously only allowed for purposes of intelligence, surveillance, and reconnaissance. The U.S. also has the authority to carry out drone strikes in Libya and Somalia, although some groups have accused the military of killing civilians.