PHILADELPHIA (CBS) — Demonstrators set fire to an American flag Saturday while marching in the streets of Center City.

Police say it happened Saturday afternoon as protesters were marching along 16th Street and John F. Kennedy Boulevard.

SEPTA Police Chief Thomas J. Nestel III said on Twitter that members of the group “Antifa” were protesting and burning an American flag.

“Antifa protesting at 16/JFK,” he said.

Antifa protesting at 16/JFK pic.twitter.com/q4faDGtDwa — Thomas J. Nestel III (@TNestel3) January 20, 2018

Nestel also tweeted that a Philadelphia police officer gathered the remains of the burnt flag that protesters left on the ground so they could be disposed of properly.

“The burned flag left on the ground by Antifa received a crisp salute from @PhillyPolice Officer who then collected the remains for proper disposal,” he said.

The burned flag left on the ground by Antifa received a crisp salute from @PhillyPolice Officer who then collected the remains for proper disposal. pic.twitter.com/GTdfap16Yn — Thomas J. Nestel III (@TNestel3) January 20, 2018

No one was said to have been injured in this incident.