Tensions in Los Angeles escalated Sunday as thousands of protesters took to the streets in response to U.S. President Donald Trump’s extraordinary deployment of the National Guard, blocking off a major freeway and setting self-driving cars on fire as law enforcement used tear gas, rubber bullets and flash bangs to control the crowd. Many protesters dispersed as evening fell and police declared an unlawful assembly, a precursor to officers moving in and making arrests of people who don’t leave. Some of those remaining threw objects at police from behind a makeshift barrier that spanned the width of a street and others hurled chunks of concrete, rocks, electric scooters and fireworks at California Highway Patrol officers and their vehicles parked on the closed southbound 101 Freeway. Officers ran under an overpass to take cover. Sunday’s protests in Los Angeles, a sprawling city of 4 million people, were centered in several blocks of downtown. It was the third and most intense day of demonstrations against Trump’s immigration crackdown in the region, as the arrival of around 300 Guard troops spurred anger and fear among many residents. The Guard was deployed specifically to protect federal buildings, including the downtown detention center where protesters concentrated. Several dozen people were arrested throughout the weekend of protest. One was detained Sunday for throwing a Molotov cocktail at police, and another for ramming a motorcycle into a line of officers.