Construction of prototypes for President Donald Trump’s controversial border wall began Tuesday south of San Diego, California.

U.S. Customs and Border Protection officials confirmed eight prototypes are under construction in the area including four made with concrete and four using alternate or other materials.

Each will be between 18 and 30 feet high.

San Diego County officials say they are prepared for possible protests and large crowds near the construction site. The Board of Supervisors unanimously approved a ban on weapons in the area.

More than two dozen San Diego Sheriff’s Department patrol vehicles were in place early Tuesday in Otay Mesa on the U.S.-Mexico border.



Temporary parking signs have been set up along Airway Road. Parking will be prohibited around the clock from September 26 through November 10.

A large open field just east of Airway Road and north of the U.S.-Mexico International Border is surrounded by temporary fencing.

Meanwhile, cement barriers block off a road directly west of the construction site to designate so-called free speech zones.



Six out-of-state construction companies will build the prototypes. NBC 7 reached out to those companies for comment, but they have not immediately replied.

Law enforcement officials said there has not been much online chatter about any planned protests or demonstrations, but the San Diego Police Department says they are preparing for the worst.

"The San Diego Police Department supports every person’s First Amendment Right to Freedom of Speech and their Right to Assemble. As part of our community policing philosophy we work closely with any party or group that wishes to express their views in a law abiding manner. We will work collaboratively with all our local, state, and federal partners to help ensure the safety of our community. However, we will not tolerate any protestors that turn to violence, vandalism or other criminal acts. Should that occur we will be prepared to take swift and decisive action,” said SDPD Chief Shelley Zimmerman in a statement.

Enrique Morones with the civil rights group Border Angels says his group is planning a bi-national church mass. A date or location for the mass has not been determined, but Morones says he is concerned about the potential of violence between demonstrators.

“If you’re in favor of the wall, you’re entitled to speak in favor of it but peacefully, and that’s what we’re asking for. We don’t want any violence, we don’t want the wall at all, but especially not now,” said Morones.

Morones called into the question the sensitivity of building the wall at this point of time, given the devastating aftermath of the earthquake in Mexico.

“Is it a time to be building prototypes on the Mexican border? It makes absolutely no sense, it shows no compassion,” said Morones.

NBC 7 asked several groups in favor of the border wall, including the group known as Patriot Fire, about the construction of the prototypes. There was no immediate comment on construction or any planned demonstrations.