A security official said police were questioning 87 suspects.
The protesters were angered by the decision of authorities in Burullus to stop distributing subsidized flour directly to residents and instead deliver it exclusively to bakeries, the official said on condition of anonymity because he is not authorized to give statements.
Fishermen in Burullus prefer to bake a type of bread suited to long fishing voyages instead of buying the standard subsidized bread from bakeries.
There have also been accusations by the government that people are selling the subsidized flour on the black market for a profit, leading to shortages.
Like much of the rest of the world, Egypt has been wracked by rising food prices and stagnant wages, resulting in protests and demonstrations.
There has also been a shortage of the subsidized bread relied on by vast segments of this impoverished country of 76.5 million.
Some 10 people were reported killed since the beginning of the year after scuffles in bread lines.