A bus ran over and injured three pedestrians then drove on and struck an 18-year old who got trapped under the vehicle, rescuers said.the Magen David Adom emergency service said

"Paramedics pronounced him dead at the scene," the agency said.

Thousands of ultra-Orthodox Jews had taken to the streets of to protest a law to conscript them to the army, as the military faces manpower shortages after two years of war on multiple fronts.

Mass demonstrations against the law have been taking place on a regular basis in recent months.

According to a police statement, Tuesday's protest turned violent after "a small group of rioters began violently disturbing public order, including by blocking traffic routes, damaging buses, setting trash bins on fire, throwing objects and eggs at police officers and Border Police, shouting invective, and assaulting journalists working at the scene".

The police added that the bus "was blocked by rioters who were... obstructing the route". The driver was arrested and under questioning alleged "that he was assaulted by rioters, after which the unfortunate incident occurred".

Israeli police sources quoted by local media ruled out concerns the event was a terror attack.

Prime Minister Benjamin Netanyahu has been under pressure from the opposition and some coalition partners to increase the number of military recruits, but ultra-Orthodox party leaders -- traditionally Netanyahu allies -- oppose the conscription of religious students, who form a large part of their constituency.

Under a ruling established at the time of Israel's creation in 1948, men who devote themselves full-time to studying Jewish texts are given a de facto pass from mandatory military service.

But this exemption has come under mounting scrutiny from the rest of Israeli society -- particularly when tens of thousands of conscripts and reservists are mobilised on several fronts, despite the fragile truce that has ended the war in Gaza.

The ultra-Orthodox make up 14 percent of Israel's Jewish population.

Keeping ultra-Orthodox parties on board is key to the survival of Netanyahu's right-wing coalition.

In November, a new draft law was put forward in the parliament's foreign affairs and defence committee, after a previous conscription bill was voted down in July.

The ultra-Orthodox United Torah Judaism party quit the government over that bill, and now Netanyahu's coalition only holds 60 out of 120 seats in parliament.

Ministers from the other main ultra-Orthodox party, Shas, resigned from the cabinet over the issue, though the party has not formally left the coalition.

In late October, a teenage boy fell to his death from a high-rise during another mass protest against the conscription law in Jerusalem. Israeli media said his death was likely to be a suicide, as the boy had left a farewell message on his Instagram account.