Officials in Niger say at least two guards were killed Saturday in an armed attack at the main prison in the capital, Niamey.
Government spokesman Marou Amadou said another guard was seriously wounded. He said several inmates suspected of terrorism were involved in the assault, and that most of the attackers are back in custody.
Amadou said an investigation has been launched to determine how the inmates obtained weapons.
It was not clear if some attackers came from outside the jail.
The attack came a little more than a week after Islamist militants carried out simultaneous attacks on a military barracks in the town of Agadez and a French-owned uranium mine in Arlit. The attack on the barracks killed about 20 people, most of them soldiers.
The Malian Islamist group MUJAO claimed responsibility for last week's attacks, as did a former North African al-Qaida leader, Mokhtar Belmokhtar. They said the attacks were retaliation for the French-led military intervention against Islamist militants in Mali.