Heavy gunfire was heard in the area around the presidential palace, which houses the presidential offices and residence, in Niamey on Wednesday morning.
The gunfire was heard around 3:00 am (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 of Niger has not yet reacted to these events.
There has been increasing attacks by militant armed 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 affirming the results.