A Philadelphia group known for Black Panther-style community patrols is fighting to restore several members’ gun licenses after the city revoked them over an encounter with police earlier this year, the group’s attorney tells Axios.

The revocations have halted the armed neighborhood patrols and escalated tensions between city officials and the group.

In Pennsylvania, owners of licensed firearms usually do not need a permit to openly carry their weapons — except in Philadelphia.

Philadelphia police sent a letter to at least four members of the Black Lion Party for International Solidarity, including its leader, Paul Birdsong, in February, indicating their gun licenses had been revoked, the members’ attorney, Lyandra Retacco, tells Axios.