"Seven Niger soldiers were killed and two others wounded in a Boko Haram attack on a village near Lake Chad yesterday night," a military report said. "Boko Haram lost 14 members."
The fighting took place in Karouga, near the border dividing Niger, Nigeria and Chad, a Chadian security source said.
According to the source, Boko Haram members later sought to enter Chadian territory by crossing Lake Chad, but Chadian aircraft intervened and destroyed their five boats.
The conflict centred in northeastern Nigeria has left more than 13,000 people dead.