09/02/2016 20:07 EDT | Updated 09/03/2017 01:12 EDT

Police union: Officers may boycott 49ers over Kaepernick

SAN JOSE, Calif. — The union for police officers who work San Francisco home games says its members may boycott policing the stadium if the 49ers don't discipline Colin Kaepernick for refusing to stand during the national anthem.

A letter sent to the 49ers from the Santa Clara Police Officers Association was obtained Friday by KNTV-TV, the NBC affiliate in San Jose.

It says that if the team "fails to take action to stop this type of inappropriate behaviour it could result in police officers choosing not to work at your facilities."

It adds that the union leadership has a duty to protect its members from harassment.

The quarterback has refused to stand for the anthem at the team's preseason games in protest of issues including racial injustice and police brutality. He said he plans to continue into the regular season.