Police dismantled a pro-Palestinian tent encampment at the Massachusetts Institute of Technology early Friday and moved to clear protesters from University of Pennsylvanias campus in Philadelphia, hours after police tear-gassed protesters and took down an encampment at the University of Arizona.

In Cambridge, Massachusetts, video showed police roaming through the MIT encampment and organizers said about 10 students had been detained. Police in riot gear arrived around 4 a.m., encircled the camp and gave protesters about 15 minutes to leave. A crowd outside the camp began gathering and chanting pro-Palestinian slogans but were dispersed by 6 a.m.

At the University of Arizona in Tucson, campus police in riot gear fired tear gas late Thursday at protesters before tearing down an encampment that included wood and plastic barriers on campus. In statement, the University of Arizona said it made the decision because the encampment violated school policy.

A structure made from wooden pallets and other debris was erected on campus property after 5 p.m. in violation of the policy, the school said in a statement. University officials issued warnings to remove the encampment and disperse. The warnings were ignored.