Sharqiya police have dispersed a Muslim Brotherhood march in the city of Zagazig.
Troops intervened after marchers attempted to set a police vehicle ablaze.
Six of the protesters were arrested.
The MB march started early Saturday following the Eidul Adha prayers in Qawmiya area.
Marchers chanted slogans against the army, police and state institutions.
Some of them hurled Molotov cocktails at a police vehicle that was slightly damaged. Troops were able to put out the flames before the car was completely destroyed.
The troops fired tear gas to disperse the crowd.
The arrested have been referred to the prosecution office.