Two men who were watched by police as they marched through a Los Angeles suburb carrying assault rifles and wearing military-style gear were later detained after a standoff that occurred when their car was stopped in the city of Los Angeles, authorities said Tuesday.

Residents began calling 911 shortly after midnight to report the two men, Inglewood police Lt. Greg Held said.

While the two carried weapons, they didn't threaten anyone, and officers decided to avoid confrontation and just monitor them, Held said.

At one point the men showed their guns off to a television news cameraman. They said the weapons, which appeared to be AR-15 assault rifles, were not loaded. In California, openly carrying an unloaded firearm is a misdemeanor punishable by up to one year in jail.

Broadcast footage showed the men, who are black, pacing through dark, empty streets, the guns slung over their shoulders, occasionally decrying racism and white supremacy.

"Let it be known that this is a peaceful protest and I'm within my constitutional rights," one of the men shouted at TV cameras. "So if they violate that, that just goes to show how phony they are."

Los Angeles police began monitoring the pair when they crossed into that city around 3 a.m.

After seeing the video of the men "with what appeared to be assault rifles, body armor, and Kevlar helmets," officials decided to detain and question them, LAPD Deputy Chief Bob Green told reporters.

Police in a half-dozen patrol cars tracked the men and pulled over their black sedan around 7 a.m. The men got out of the car, but initially failed to comply with the officers' commands. Police used a non-lethal device — apparently rubber bullets — in taking the driver into custody, according to City News Service. The passenger sat down on a curb and was taken into custody.

The men, who were not identified, were not charged and the incident was under investigation, officials said. Detectives will try to determine what the pair's intentions were and whether their guns were legal, Green said.