The 200-year-old festival coincides with El Día de los Inocentes, Innocents' Day in English, Spain's version of April Fool’s.
Under the slogan of 'New Justice', a group of married men take siege of the Valencian town and impose a series of ridiculous laws on residents.
Those who don't abide by the new laws set by the Enfarinats, the 'Flour Police', are given unofficial fines.
A battle of eggs, flour and firecrackers is then waged between the Enfarinats and La Oposició, another 'army' which tries to restore order in Ibi.
At the end of the day, all the money collected from the 'fines' is donated to charitable causes in the town.