Abdou Moumouni University in Niamey was reopened on Saturday after President Mahamadou Issoufou held talks with student leaders in a bid to defuse the crisis.
The campus had been closed since hundreds of unhappy students joined a demonstration Monday demanding better living and studying conditions.
The protest paralyzed traffic as demonstrators set up barricades of tree trunks, blocks of stone and burning tires, mainly on the right bank of the River Niger where the campus is located.
Security forces used tear gas to disperse the demonstrators, who responded by throwing stones, according to images shown on local television.
One protester died after a fall which was not linked to police action, the authorities said, but the students' union insisted the death was a result of the student having been hit by a police tear gas canister.
An inquiry has been opened.
National police spokesman Adily Toro told reporters that the three officers were arrested over another incident involving a protester.
They have "broken the laws and the rules of the republic" and "will answer for their acts before competent courts", Toro said.
A video posted on social media and broadcast on private television stations shows police officers hitting a protester while forcing him to chant: "Long live the police."
According to official figures, 313 people were arrested, but 140 have since been released. A total of 109 people were injured, including 88 protesters and 21 police.
The government also reopened another university in the central city of Maradi, Niger's third largest, which had also been shut down because of student protests.