Police in a central Chinese city have added a new task force to their crime patrol unit: citizen volunteers.

More than 19,000 residents in Changsha, the capital of Hunan province, signed up Tuesday to patrol arm-in-arm with local police as part of the program’s most recent recruitment drive, Sixth Tone’s sister publication, The Paper, reported. Locals must first register on the Xingcheng Yuanding — or “Star City Gardener” — app to volunteer, after which they are assigned to specific patrol duties.

Over 55,000 residents of Changsha have volunteered for the role since the city’s public security bureau launched the program in March. Police said they have received “tips and clues” leading to the arrest of several suspects, according to the report.

This isn’t the first time law enforcement agencies have collaborated with the public to expand their crime-busting measures. In 2016, Beijing’s public security bureau launched an app called The Chaoyang Masses, which allowed individuals to send police tips about suspicious activities. The app’s name has now become synonymous with an army of over 130,000 volunteers who go on security patrols to keep their neighborhoods safe. (Image: Courtesy of Changsha police)