Heavy gunfire was heard in the area around the presidential palace in Niger’s capital, Niamey, in the early hours of Wednesday.
The gunfire was heard at around 03:00 local time (02:00 GMT), and it lasted at least 15 minutes before stopping, followed by small arms fire, local residents said.
The situation remains confused and the city is on high alert.
The shooting took place less than 48 hours ahead of the inauguration of newly elected President Mohamed Bazoum.
The government has not yet reacted to these events.
There have been increasing attacks by militant groups as well as political tensions in the country following Mr Bazoum’s victory in February’s presidential election.
His challenger and former President Mahamane Ousmane, who lost in the run-off, has rejected the results and denounced a court ruling upholding Mr Bazoum’s victory.