Federal agents fired pepper balls at protesters outside Delaney Hall in Newark on Monday following days of unrest outside the privately run immigration detention center. U.S. Sen. Andy Kim said he had trouble breathing from the cloud of pepper spray deployed as a growing crowd of protesters responding to an inmate hunger strike demonstrated outside.

Protesters outside a New Jersey migrant detention center where a hunger strike is under way alleged that US immigration agents deployed pepper spray and batons against them during a demonstration on M...