Police told residents and vendors at the scene that the event was being staged and not to panic.

Huang Wenhui, head of the public security bureau, said it mobilized nearly all police staff members to help with the boy's special day out.

"The Chinese dream can only be realized if everybody's dream comes true," Huang said.

Muscular dystrophy is a disease that leads to loss of strength, the loss of muscles and disability. Junyi can only move by crawling.

His mother, Chen Qingmei, said: "He has dreamed of becoming a policeman since he was a child. I am very grateful for everything people did for him."

Both Junyi's parents are migrant workers on low incomes. The family's monthly income is about 5,000 yuan ($830) and it can hardly make ends meet as it has spent 600,000 yuan on treatment for the boy's disease.

Junyi's teacher, He Jianjun, said, "Although he has the disease, he studies hard and makes every effort to finish his homework."

The story spread widely on the Internet, with people in China and overseas hoping to help the boy.

Chen said, "A Chinese woman surnamed Wang, who is living in Japan, called me and said she wanted to help us.

"With the help of so many people and society, I believe Junyi will recover and realize his dream of becoming a policeman."

In November, residents of San Francisco arranged a similar event for a 5-year-old boy fighting cancer, helping him to become a Batman-like "Bat Kid" for the day.

Junyi, 9, is part of the swearing-in ceremony for the Xinyu Public Security Bureau, East China's Jiangxi province, on Jan. 11, 2014. The 9-year-old boy, who suffers from a serious brain disease, dreams of being a police officer and "catching bad guys". The Xinyu Public Security Bureau gave the boy a chance to experience real police work. [Photo by Zhang Min/Asianewsphoto]