Gunfire has been heard coming from the airport in Niger's capital, Niamey, according to residents.
It began around 06:00 local time (05:00 GMT) and Reuters says the blast lasted about an hour.
Witnesses told AFP that the shots were coming from the airport's entrance.
For a decade Niger has been fighting an Islamist militant insurgency; a January attack on the same airport was blamed on jihadists linked to the Islamic State, but no group claimed responsibility for the Thursday incident.
The authorities have not yet commented, and the country remains trapped in a cycle of violence under a military junta.
