Castillo’s supporters marched around the South American country and set up street barricades to demand new elections and the ouster of current leader Boluaarte.
President Boluarte, who belongs to the same leftist party as Castillo, has insisted she will not step down.
Peru has faced political instability in recent years, with Bolurat, 60, the sixth person to hold the presidency in five years.
Castillo, who has been under investigation for several frauds during his tenure, has been remanded in custody for 18 months on charges of sedition.