TEHRAN, Young Journalists Club (YJC) - "Last night at 2 a.m. local time, a group of terrorists attacked the small building where a Foraco team was sleeping and killed seven of them, plus one civil servant," the company said in a statement.
Five other employees were wounded, with two in serious condition, it said. The workers were drilling two deep water wells for the water ministry in southeastern Niger's Diffa region.
A security source told Reuters that the assailants were believed to belong to Nigerian extremist group Boko Haram, which is active near the border with Nigeria.
Boko Haram has been trying since 2009 to establish an Islamic state in northeast Nigeria and has launched repeated attacks into neighboring Niger, Chad and Cameroon.
Thousands of civilians have died in the violence.
Marseille-based Foraco is listed on the Toronto Stock Exchange and says it is the third largest global mineral driller with mining and water projects across 22 countries.