Law enforcement officers massed by the hundreds on the campus of the University of California at Los Angeles after darkness fell on Wednesday in preparation to clear out a pro-Palestinian protest camp attacked the night before by pro-Israel supporters, Reuters reports.

Live television footage showed police in tactical gear filing onto the UCLA campus adjacent to a complex of tents occupied by throngs of demonstrators. Some of the activists were seen donning hard hats, goggles and respirator masks in anticipation of the raid a day after the university declared the encampment unlawful.

Hundreds of other pro-Palestinian activists assembled outside the tent city jeered police with chants of “Shame on you,” some banging on drums and waving Palestinian flags, as officers marched onto the campus grounds. Many of the demonstrators wore the traditional Palestinian keffiyeh scarves.

Before moving in, police with a loudspeaker urged the demonstrators to clear the protest area in a grassy plaza between the landmark twin-tower auditorium Royce Hall and the main undergraduate library.

UCLA had canceled classes for the day following a violent clash late Tuesday night and early Wednesday morning between the encampment’s occupants and a group of masked counter-demonstrators who mounted an assault on the tent city with sticks and poles.

The occupants of the outdoor protest camp, set up last week, had remained otherwise largely peaceful before the melee, which university officials blamed on “instigators,” vowing an investigation.