Abuja, June 19 (RHC)-- At least 40 civilians have been killed after Boko Haram Takfiri militants attacked two villages in southern Niger, an official says. Boko Haram militants, based in Nigeria, attacked two villages in southern Niger's Diffa region Wednesday night, Diffa Governor Yakouba Soumana Goah said Thursday. After killing the villagers, the militants set fire to their houses in the villages.

The army forces have launched an operation in pursuit of the attackers, the governor said. Boko Haram Takfiri militants last attacked Niger in April, killing at least 58 people.

The latest assault was the second Boko Haram cross border attack in the past week. On Monday, the militants carried out twin bombings in Chad's capital, N'Djamena, killing at least 34 people, injuring more than 100 others.

Meanwhile, Chad's military said on Thursday that it had carried out several airstrikes on Boko Haram positions in neighboring Nigeria on Wednesday.

Since March 8th, Chad together with Niger, Cameroon and Nigeria has been conducting a coordinated offensive against Boko Haram militants in Nigeria's Borno State.

Boko Haram's leader Abubakar Shekau had repeatedly threatened to attack Chad and other countries that joined forces against the terrorists.

The Takfiris has claimed responsibility for a number of deadly attacks and bombings in various parts of Nigeria during the past six years. The Takfiri militancy has since claimed 15,000 lives and forced 1.5 million from their homes.