The Sunni jihadist group killed an estimated 10,000 people last year in its drive to create an Islamic emirate in northern Nigeria.
Niger's parliament approves the deployment of more than 3,000 troops to tackle Boko Haram in northern Nigeria.
The fighting took place where Chad has sent hundreds of troops to help Niger take on Boko Haram.
French reconnaissance flights are beingconducted along Nigerien and Chadian borders as part of wider Sahel strategy.
Nigeria's military has reportedly agreed a truce with Boko Haram, in a deal that may also see the release of 200 schoolgirls taken hostage by the Islamist group