A state security agent says that a group of masked gunmen opened fire at the entrance to the central prison in Niger's capital, and fought their way inside the complex.

Niger security agent Souleymane Magagi said some prison guards fell and were either wounded or dead, though he could not be sure because he ran for cover.

An Associated Press reporter who rushed to the scene was unable to approach because the roads leading to the prison had been roped off.

The prison assault comes less than two weeks after Islamic extremists carried out one of the boldest attacks in recent years when suicide bombers infiltrated both a military camp in the Nigerien city of Agadez and a French-operated uranium mine, killing 35 people, include the attackers.