Heavily armed men have stormed a prison in southwestern Nigeria using grenades, the facility said on Saturday, with unconfirmed media reports saying that nearly a thousand inmates had escaped. “Gunmen that came in large numbers” attacked the Abonlogo correctional facility with grenades on Friday evening, Olanrewaju Anjorin, an administration spokesman for the prison in Oyo State, told AFP. “A lot of inmates were re-arrested after the attack, and it is still ongoing,” he said, without specifying how many prisoners had escaped, or confirming whether there had been any casualties. The police will issue a statement with more details about the attack soon, he added. Several local media outlets reported that almost 1,000 inmates were released during the attack. It was not yet possible to verify those reports. Africa’s most populous country has struggled with rampant insecurity, with larges swathes of its territory under the control of criminal groups. About 240 prisoners were broken out during an attack on another prison on September 13 in Kogi State in central Nigeria. In April, more than 1,800 inmates escaped during an attack on yet another prison in the southeast.