PORTSMOUTH, Va. — The Portsmouth city manager has resigned amid an ongoing dispute over charges filed against a Black state senator and several others who the city's police department say were conspiring to damage a Confederate monument.

Lydia Pettis Patton, who announced last month that she would be retiring at the end of the year from her role, announced her departure in an email Tuesday morning, The Virginian-Pilot reported.

Pettis Patton wrote that her decision to "step aside immediately" was in "the best interest" of the city. "I have served this city with honor and dedication and I want to leave the city as I came in 1986 with honor," the newspaper quotes Pettis Patton's email as saying.

Pettis Patton was the first Black woman appointed to the position, a role she had held since 2015. Her resignation came hours after the city's mayor called for a special meeting to discuss "personnel matters."

Officials did not provide details on that meeting, but one of the city's top officials, Portsmouth Police Chief Angela Greene, was placed on administrative leave Friday, nearly three weeks after her department charged several people, including State Sen. Louise Lucas, members of the local NAACP chapter and the public defender's office with conspiring to damage the monument in June.

A rally in support of Greene was held outside the Portsmouth City Hall on Sunday.

The felony charges levied against Lucas are based on words police say she spoke before protesters ripped heads off Confederate statues in Portsmouth and pulled one down, critically injuring a demonstrator. Lucas and several others face counts of conspiracy to commit a felony and injury to a monument in excess of $1,000.

In a statement posted last month on Facebook by Portsmouth Vice Mayor Lisa Lucas-Burke, Lucas' daughter, Pettis Patton said she was "surprised and troubled" that the investigation into the incident had continued despite there being a "conflict of interest" that was reported by the police chief.

"Chief Greene and members of the Police Department continued to be engaged without my knowledge," Pettis Patton wrote.