Protests against Nepal’s short-lived ban on social media grew increasingly violent Tuesday as demonstrators set government buildings and politicians’ homes on fire and attacked some leaders.

Nepal witnessed one of its most intense protests recently, with 51 people killed across the country and hundreds injured.

The group alleged that “over the bodies of the martyrs of the Gen-Z movement, a grave reactionary conspiracy is being staged — under military mediation to restore the monarchy and to abolish seculari...