Niger's defense ministry says three gendarmes were killed and four security forces injured in separate attacks this week. In a statement on Thursday night, the ministry said unidentified gunmen in a pick-up truck and on motorbikes struck gendarmes on Wednesday night near the country's western border shared with Mali and Burkina Faso. One officer was injured. [related-post] Earlier on Wednesday night, suspected Boko Haram militants hit near the town of Bosso in a region that has come under regular attack by the Nigeria-based extremists. Three security forces were injured while five assailants wearing explosive belts — three of them women — were killed. Niger plans to close its borders for a presidential runoff vote scheduled for Sunday. President Mahamadou Issoufou is running for a second term.