Hundreds of ultra-Orthodox protesters took to the streets in Jerusalem to demonstrate against conscription.
The police say the protesters hurled stones and bottles at them and set rubbish bins on fire.
A new law which was passed last week will end their exemption from conscription which is almost as old as the state itself.
Police on horseback pushed the protesters back and five were arrested. The demo was reportedly staged as a show of support for an ultra-Orthodox man who refused to appear at a recruitment centre.
The sons of Israel’s secular majority serve three years mandatory military service from the age of 18.
Ultra-Orthodox leaders say they serve their state through religious study and prayer and fear integration into the military will pose a threat to their pious way of life.