Violent protests in downtown Portland, Oregon, are expected to continue Monday, marking the 40th night of demonstrations that took a turn for the worse over the holiday weekend as commercial-grade fireworks were shot at police officers and explosives and machetes were found on arrestees.

In what the U.S. attorney for the district of Oregon described as a “significant escalation in violence,” demonstrators over the holiday weekend targeted judicial buildings. The crowd hurled firebombs, incendiary devices, and explosive mortars at the Hatfield Federal Courthouse and Multnomah County Justice Center in an attempt to burn it down or break-in. Others used baseball bats to break down the doors, which were later boarded up by the city.