Pictures and objects are displayed at an exhibition held by The Memorial Hall of the Victims in Nanjing Massacre by Japanese Invaders in Nanjing, Jiangsu province. [Photo/WeChat account:jng1937]

The Memorial Hall of the Victims in Nanjing Massacre by Japanese Invaders in Nanjing, East China's Jiangsu province held an exhibition about the museum's volunteers on April 27.

A number of pictures, videos and objects were displayed to show visitors how the volunteer group has developed and stories of several volunteers.

Volunteers put paper purple grass, a symbol of peace, on a floral decoration during the opening ceremony. [Photo/WeChat account: jng1937]

Founded in 1994, the purple grass volunteer group now has more than 20,000 members from 35 countries. In the past 27 years, the volunteers have participated in over 137,000 activities and helped 73.26 million visitors to the memorial hall.

A Pakistani volunteer Yongqiang participate in the opening ceremony of the exhibition. [Photo/WeChat account: jng1937]

A Pakistani volunteer, whose Chinese name is Yongqiang, decided to be a purple grass volunteer after visiting the memorial hall. He and his friends also shared their experiences as volunteers on a YouTube channel to show people around the world that Chinese people value peace and how the memorial hall was built to spread peace.

Zhang Jianjun, head of the museum, said he hopes more professional volunteers could join purple grass volunteer group and work together to promote peace.