Federal agents stand guard outside an ICE facility in Portland, Oregon, on Monday night.

About a dozen federal officers from Department of Homeland Security, Border Patrol, and Immigration and Customs Enforcement were providing security Monday night at a Portland ICE facility that has been the site of protests for months.

This is the facility where the Trump administration has been trying to send National Guard troops, arguing a deployment is necessary to protect federal immigration personnel and property amid protests over the administration’s sweeping crackdown on undocumented immigrants — despite state and city leaders’ insistence that the protests have been largely peaceful and any violence has been dealt with by local law enforcement. A federal judge has blocked any deployment of federalized National Guard members to Portland until at least October 19.

Many of the federal officers providing security outside the Portland facility Monday night were in military-style tactical gear, with ICE, DHS, and Border Patrol decals and patches clearly visible on their uniforms.

During the day, it has been a completely different scene, with far fewer officers and no heavy gear.

Flare-ups have happened when vehicles enter or leave the property. Those vehicles contain federal officers coming and going from shifts. CNN’s crew has not seen any detainees being brought in.

Each time a vehicle pulls out of the driveway, about a dozen officers come out wearing gas masks, with tear-gas canisters strapped to their vests. Several hold pepper ball guns. They push back a small group of protesters standing at the base of the driveway, and that move draws a crowd every time.

Protesters confront federal agents outside an ICE facility in Portland, Oregon, on Monday night.

Officers also have been posted on the roof, and we have seen some aggressively fire pepper balls at the few screaming protesters standing just behind a blue line painted on the pavement marking federal property. When that happens, the gas hangs over the immediate area just outside the ICE facility. Several people nearby started coughing. You can taste and feel the sting of gas in the air.

At one point, a group of federal officers came rushing out of the gate and grabbed one protester, detaining that person before quickly retreating inside the property.

Portland police also have been out here here, but their posture could not be more different. Most of the officers standing around are not in tactical gear. A few bike officers wear their standard equipment, but we have not been seeing any kind of aggressive or mirrored response from the city side.

Some of them have been standing among the crowd, watching, talking with people, even blending in. Their crowd-control and rapid-response teams are nearby, but they are not engaging or reacting to what the federal officers are doing.

A heated moment came when a protester burned an American flag, sparking a shouting match between Trump supporters and ICE protesters. Portland police calmly stepped in and broke it up without escalating it.

We were out until about 10 p.m. Monday local time (1 a.m. ET Tuesday), and by then, the scene had taken on a strange mix of tension and normalcy. People were cooking cheeseburgers. Trump supporters were grilling, holding American flags, and one flag had a message offering thanks to federal officers.

At the height of the gathering outside the facility Monday night, there were maybe 80 to 100 people total — a mix of media, protesters, Trump supporters, and onlookers, all within a single block.