Gunmen killed two people and freed 175 prisoners in an attack on a prison in the south of Nigeria, dpa reported according to the Nigerian Tribune newspaper.
About 30 armed men blew up one of the walls of Olokuta Medium Security Prison in Ondo state capital Akure and stormed the facility.
Several warders were injured in the attack.
"We cannot specifically identify those behind the attack," said Ondo state prison controller Tunde Olayiwola.
Residents of Akure believe Islamist sect Boko Haram was behind the attack, the newspaper said.
The extremist group has raided prisons in Nigeria in the past few years.