In 1955, the following barrios were created:[5] In May 2003, the municipality was attacked by 150 Moro Islamic Liberation Front (MILF) and Abu Sayyaf guerrillas.

A small group of policemen led by 27-year-old police senior inspector Ranie Planilla Hachuela defended Siocon during the assault, which lasted nine hours.

Hachuela managed to rally his men in putting up stiff resistance against the wave of attacks by the rebels trying to overrun the municipal hall, police station, and hospital.

That frightening feeling was expressed by Wiljun "Pido" Cubero as he narrated how the rebels stormed the municipal hall and fire station right next to their house at Micubo's compound.

Some hostages were released hours later, while other strong men were held for days as they were tasked to carry wounded rebels through the thick forest in the municipality of Sibuco.