Demonstrators tried to rip down a poster at the Patriots Day rally in Berkeley, California, on Saturday, April 15.The rally was held in Martin Luther King Jr. Civic Center Park and was sponsored by the pro-DonaldTrump group Liberty Revival Alliance, reported The Los Angeles Times.The crowd quickly grew to more than 200 people, with anti-Trump protesters facing off with the president’s supporters. Plastic netting was used to divide the two sides, and that was torn down. Berkeley police told KQED four people were arrested, at the time of writing, and contraband was seized.Firecrackers were also thrown into a large crowd and pepper spray was used during the rally.