They're the strong and the proud, but the Marines aren't free to stand on the streets of San Francisco.

The Silent Drill Platoon of the U.S. Marine Corps wasn't allowed to be filmed Sept. 11 on California Street for a segment of its new advertising campaign, a Marine spokesman told FOXNews.com.

Instead, the elite group took its austere display to the Golden Gate National Recreation Area for the final segment of its "America's Marines" TV commercial. The group is on a two-month nationwide tour as part of the campaign.

Stefanie Coyote, the executive director of the San Francisco Film Commission, the group responsible for issuing film permits, was unavailable for comment Tuesday.

Coyote told KGO-TV that "traffic control was the issue."

The film commission did allow the Marines' production unit to film the street without Marines. They'll be superimposed in the spot, KGO-TV reports.

Her office referred calls to San Francisco Mayor Gavin Newsom's press office.

"The Marines were not denied a permit to film in San Francisco," said Nathan Ballard, director of communications for the mayor, adding, "we really appreciate their business and they're invited back anytime."

Meanwhile, the Silent Drill Platoon continued its campaign, filming a portion of the commercial Monday in New York's Times Square during the early morning rush hour.

The platoon is documenting its journey on the Web site www.Our.Marines.com and plans to film portions of the commercial in Sligo, Ky., on Oct. 6, in the Grand Canyon and at Hoover Dam on Oct. 22 and in the Rocky Mountains on Oct. 30, according to the group's online schedule. The public is invited to attend.