Photo/Illutration A delivery driver on Sept. 20 brings a bouquet of flowers to a Japanese school in Shenzhen, China, in tribute to a boy who was fatally stabbed. (Yohei Kobayakawa)

SHENZEN, China—Workers on motorcycles have continued to deliver bouquets of flowers to a Japanese school here for “secret” tributes to a 10-year-old boy who was fatally stabbed near the site.

One driver dropped off flowers on the morning of Sept. 20, two days after the fatal attack.

“Since yesterday, I’ve made seven or eight deliveries. Some are from customers in Wuhan (in Hubei province) and Shanxi province,” he said.

Although the attack on the boy was not reported by major Chinese media outlets, information about his death on Sept. 19 spread through social media.

The number of people offering flowers at Shenzhen Japanese School, where the boy attended, has since increased. Even people in distant parts of China are apparently using delivery services to offer flowers and pay respects.

However, the flower givers have tended to prefer anonymity, and some have even backed out from presenting the flowers. They are apparently worried their acts of compassion could result in possible repercussions from Chinese authorities.

A 30-year-old man who visited the site with a bouquet of flowers on Sept. 19 was surprised to see “so many public security police.”

Dozens of people were standing near the school. Plainclothes authorities appeared to be among them.

“I may be in trouble (with the police) in a couple of days,” the man told me. “But I want to say that ordinary people think that incidents like this should not happen.”

A 54-year-old man who also offered flowers on Sept. 19 said, “As a Chinese, I condemn (the attacker’s actions).”

But he had a request.

“Please don’t take a picture of my face. It will be troublesome,” he said.

On Sept. 20, at a flower shop near the school, an elderly man was writing “May he rest in peace” on a message card to accompany a bouquet of flowers.

According to a female employee at the shop, the flowers for such offerings were sold out on Sept. 19, and people in Beijing and Tianjin have been ordering flowers online to be delivered to the school.

However, one young man who bought a bouquet apologetically offered to return it to the shop.

“Authorities are taking pictures. It's not good because I work nearby,” he said.

When he learned that he was talking to a Japanese reporter, he bowed and said, “I’m sorry.”

Outside the shop, a man wearing sunglasses had a camera-like object attached to his waist pointing toward the store.

When I asked what he was doing, he simply said, “I came to check,” and walked away.

Chinese authorities have arrested a suspect in the killing of the boy, but they have not revealed a motive for the crime.

Anti-Japan posts appeared on Chinese social media before the attack. And after the boy’s death, anti-China posts spread on social media in Japan.

Concerns have risen that the incident could affect Japan-China relations.

The topic appears so sensitive in China that people are worried about offering flowers at the crime scene and answering questions from the media.