Niger's interior ministry said it had ordered search units to be on alert after inmates escaped on Thursday from the high-security Koutoukale prison whose inmates include Islamist militants.

The ministry statement did not say how many prisoners had escaped Koutoukale, which lies 50 km (30 miles) northwest of the capital Niamey, or how they had done so. In 2016 and 2019,attempted jail breaksat the facility were repelled.

The prison's inmates include detainees from the West African country's conflict witharmed groups linked to al Qaeda and Islamic Stateand suspected Boko Haram insurgents.

Local authorities imposed an overnight curfew in the urban commune of Tillaberi, which is in the same region as the prison, but did not give further details.

Niger and its neighbours in the central Sahel region are on the frontlines of the battle to contain a jihadist threat that has steadily grown since 2012, when al Qaeda-linked fighters first seized parts of Mali.

Thousands have been killed in the insurgencies and more than 3 million displaced, fuelling a deep humanitarian crisis in some of the world's poorest countries. (Courtesy, excluding headline, Reuters)