Sierra Leone has been placed under a nationwide curfew after armed men broke into prisons, setting inmates free.

Detainees from several "major" facilities were released on Sunday morning, said the West African nation's information minister.

President Julius Maada Bio later said most of the leaders behind the attack had been arrested.

In a televised address, he described the events as a "breach of security" and an attack on democracy.

He carefully avoided calling them an attempted coup.