Information about China's deadliest mass killing in years remained heavily censored as authorities in a southern city cleared candles and flowers from the memorial to the 35 people dead.
Footage showing bodies lying on the pavement appeared on social media in the hours after the crash but had soon vanished.
Officials took nearly 24 hours to reveal that dozens had died, in what was one of the country's deadliest incidents in a decade.
Chinese authorities have offered little information about the 62-year-old driver who rammed his vehicle into a sports complex in Zhuhai on Monday, mowing down people as they were exercising.
A further 43 people were severely injured in the attack.
They said the man, who was arrested as he fled the scene and identified only by his surname Fan, was upset about his divorce settlement.
Swift removal of videos from on the ground
The fatal crash happened on the eve of China's largest air show, which is held in Zhuhai — a major event promoted by the country's tightly controlled state media outlets.
The ruling Communist Party heavily monitors social media platforms, where it is common for words and topics deemed sensitive to be removed — sometimes within minutes.
Images and footage of bloody victims moments after the incident were swiftly removed from the popular platform Weibo on Monday night.
Videos of the aftermath posted to China's equivalent of Instagram, Xiaohongshu, were also taken down.
"This is a top-tier destabilising incident as defined by the central authorities," Lynette Ong, distinguished professor of Chinese politics at the University of Toronto, told the ABC.
"Because it affects a lot of people … it is as grave as a terrorist attack.
"National security, social stability these days take precedence. It's the number one priority for all the government units."
After the Chinese authorities finally revealed the death toll, the hashtag "Man in Zhuhai rammed the crowd causing 35 deaths" soon jumped to the top trending topic on Weibo and reached 69 million views within an hour.
The state-backed newspaper Global Times on Wednesday morning published a short story on the "car ramming case" on page three — a stark contrast to the front page feature on fighter jets at the air show nearby.
The Communist Party's People's Daily included Chinese President Xi Jinping's instructions to treat injured residents and punish the perpetrator in a short block of text on its front page.
Mr Xi has urged all local governments "to strengthen prevention and … prevent extreme cases from occurring, and to resolve conflicts and disputes in a timely manner", according to the official Xinhua news agency.
State broadcaster CCTV's flagship evening news program, Xinwen Lianbo, on Tuesday spent about 90 seconds on Mr Xi's directive to "treat those injured" during the 30-minute show, but shared no footage from Zhuhai.
Removal of flowers and candles
AFP reporters on the scene in Zhuhai late on Tuesday night saw delivery drivers placing online orders of flower bouquets beside flickering candles to commemorate the victims.
But just a few hours later, cleaning staff cleared away the memorial, with some telling AFP they were acting on an "order from the top".
A handful of people at the site were blocked from taking videos by a police car and security guards shouting: "No filming!"
Mr He, a local flower shop manager, said he attempted to deliver nine wreaths made from 4,500 chrysanthemums but was directed to a funeral home, which also refused to accept the flowers.
Uniformed and plain-clothed police monitored the area and prevented visitors from gathering or taking photographs.
Residents who lingered for longer than a few minutes were asked to leave. Some visitors continued to lay flowers, but the bouquets were quickly taken away.
"May there be no thugs in heaven," said a message seen on one bouquet before it was moved from public view.
"Good deeds will be rewarded and evil deeds will be punished."
Residents near the site expressed shock that a mass killing had happened in their neighbourhood.
"My husband goes jogging there every night," resident Dong Chilin told the Associated Press.
"I called him immediately … Fortunately, none of the people I know was there that day."
Another woman, who only gave her last name as Guan, said she had passed the site on Monday night but had thought it was just a traffic accident.
"Of course, this was very shocking," she said. "It was very horrible."
History of costly censorship
Videos, quickly censored inside China, circulated outside the Great Firewall.
Most were posted by "Teacher Li", an artist-turned-dissident whose X account has 1.7 million followers and posts crowdsourced videos about news in China.
Articles from Chinese media featuring interviews with survivors were quickly taken down.
"The government doesn't allow for any public expression of emotions," said Professor Ong.
"People are going to bottle up their emotions and one day it's going to erupt with another, even more violent incident."
China has a long history of clamping down on the spread of information, sometimes leading to costly delays in response.
Authorities in 2008 worked to stifle news of contaminated milk that poisoned about 300,000 children — days before the start of the Beijing Olympics.
The Chinese government that year also restricted foreign media access when protests broke out after an earthquake in the south-west Sichuan province killed an estimated 70,000 people.
Chinese censors also delayed an early response to COVID-19, penalising local health officials who warned of a fast-spreading coronavirus.
ABC/wires
