The two buses crashed into each other for unknown reasons on a highway just north of Nigeria on Friday.
According to Niger's national news agency ANP, the death toll could rise as more than 30 people have been reported injured.
Last year, more than 1,200 people died in the more than 7,000 reported road accidents in the West African country, and authorities have launched a road safety campaign to get residents to drive more slowly on the often poorly maintained roads.
