Dozens of people caught riding on U.S. Marine property east of San Diego had their bikes confiscated this weekend, with some saying that they didn’t know the area was off-limits.

Brady Emberger was with friends on Sunday, riding his bike through a Sycamore Canyon Preserve trail like he’s done a dozen times before.

This time, however, there was trouble.

Emberger and his friends were detained, ticketed and had their bikes confiscated because they unknowingly rode onto federal land; specifically, Marine base property in Miramar.

Emberger said armed officers detained people in the group and slapped each of them with a $500 citation.

“We’re kind of confused because the trails that we came into in Sycamore Canyon – they had no signs saying you’re entering government property where we came in,” he said.

Then, authorities escorted them off the land and confiscated their bikes, leaving them to hike a couple of miles to the nearest roadway, where some friends could pick them up, Emberger said.

This isn’t the first time this has happened.

The San Diego Mountain Biking Association issued a warning on Saturday, saying authorities had begun enforcing trespassing.

The warning said 15 mountain bikers had recently had their bikes confiscated. In actuality, military officials said they confiscated more than 45 bikes this weekend.

“Make sure you stay clear of this area, so you don’t have to go through what we went through yesterday,” Emberger said.

Meanwhile, Emberger is among a number of mountain bikers who must appear in court and pay the fine to get his bike back.

In a statement Monday evening, MCAS Miramar stated: "MCAS Miramar has diligently worked in alerting the community of off-limits areas and have posted signs and warnings across the government property to further increase awareness. Similarly, Military Police Officers patrol the area regularly."

A Miramar spokesman went on to state that officials confiscated 45 bikes and three motorcycles over the weekend, which will be returned once the defendants' cases are resolved.

"It is imperative that anyone who bikes on the eastern border of the base understand that this is part of an active military training area," the statement says. "We have and will continue to work with community organizations, such as the San Diego Mountain Biking Association, to help educate and deter people from coming onto the base illegally."