This was announced by city police on their Twitter page.

“Unfortunately, since the demonstrators throw stones, bottles and construction supplies, the police had to use tear gas,” the statement said.

ALERT ⚠️: Unfortunately, because demonstrators are throwing rocks, bottles and construction equipment, police had to deploy tear gas. Currently, I-4 is closed between Ivanhoe & Amelia Ave. pic.twitter.com/U3HswCUeKy

- Orlando Police (@OrlandoPolice) June 1, 2020

Earlier it was reported that the governor of the US state of Arizona, Doug Dewey, decided to impose curfews throughout the region due to riots caused by the death of African-American George Floyd