The offensive came after Boko Haram leader Abubakar Shekau pledged allegiance to the Islamic State group in an audio message.
Thousands of troops from Niger and Chad are currently stationed in Diffa in a bid to quash the Nigerian militant group which has undermined security in the region with cross-border attacks, kidnappings and killings.
Troops were seen early Sunday moving towards the Nigerian border.
Local residents also reported that aircraft had targeted Boko Haram positions on Saturday and early Sunday.
