Police removed barricades and have begun dismantling the fortified encampment of pro-Palestinian demonstrators’in a chaotic and tense scene at the University of California, Los Angeles. Hundreds of protesters early Wednesday defied orders to leave and formed human chains as police fired flash-bangs. Some people were detained and bound with zip ties. Officers spent hours threatening arrests over loudspeakers if people did not disperse. Protesters and police shoved and scuffled. Tent encampments of protesters calling on universities to stop doing business with Israel or companies they say support the war in Gaza have spread across campuses nationwide in a student movement unlike any other this century.