Military service is mandatory for most Jewish Israeli men, but the ultra-Orthodox often receive exemptions in order to continue their religious studies.

The exemptions have long infuriated secular Israelis, but ultra-Orthodox communities have resisted repeated attempts to force them to register for the draft.

During Thursday's protest, the black-clad religious demonstrators blocked traffic at a main intersection near the entrance to the city and chanted: "I will not join the army of destruction.''

Police said they were trying to restore order. There were no immediate reports of violence.