Police Commissioner Kobi Shabtai on Wednesday ordered an increase of troop presence in Lod and several other mixed Jewish, Arab cities.
Lod was declared under a "civil emergency" on Monday after a second day of rioting by Arab residents who attacked their Jewish neighbors and vandalized city property.
Under the emergency provision, police forces have wider authority to act against the rioters.
"We are witnessing a situation that we had never seen before," Shabtai said. "This includes nationalistically motivated violence, and acts of vandalism against religious and state institutions, road blockages and attempts to harm members of the police," the commissioner said.