OUAGADOUGOU (Reuters) - Gunmen killed 10 Burkinabe gendarmes in a village near the Malian border this week, Burkina Faso’s security ministry said, in a further sign of deteriorating security in a country once seen as one of the region’s more stable.

The assailants attacked and set fire to a school on Wednesday night in Loroni, a village about 250 km (155 miles) northwest of the capital Ouagadougou, the ministry said in a statement late on Thursday.

Two patrols of gendarmes, or military police, were sent to arrest the attackers but ran into an ambush on Thursday morning that killed 10 of them and wounded an unknown number of others, it said.

Security has worsened in Burkina Faso in recent months, primarily due to Islamist militant attacks near the landlocked country’s porous border with Mali. Ouagadougou has also been hit by several major attacks over the past three years.

Thousands of people have fled their home as a result of the attacks and reprisals by Burkinabe security forces, Human Rights Watch reported in May.

Violence in West Africa’s semi-arid Sahel region continues to mount five years after France intervened in Mali, a former French colony, to drive back Islamist militants who had seized the country’s desert north.

France retains about 4,000 troops deployed across its former colonies in the arid Sahel region as part of the anti-terror Operation Barkhane.