A view of the memorial service desk at the home of Xiao Siyuan, one of the four PLA soldiers killed in the last year's border clash with India, in Yanjin county in central China's Henan province Sunday, February 21, 2021.
CNN  — 

China has detained at least six people for allegedly defaming four servicemen killed in a bloody border clash with India last June, as state media wages a propaganda campaign hailing the dead troops as martyrs.

Police said six people were detained for up to 15 days across China, with another accused currently living overseas facing detention upon their return.

Under Chinese President Xi Jinping, the government has cracked down on voices that criticize national heroes or question the official narrative about them.

In 2018, China passed a law that bans people from “insulting or slandering heroes and martyrs.” Originally a civil matter, the law will be made a criminal offense in an amendment to the country’s criminal law, which comes into effect next month. Under that amendment, people who “insult, slander or use other means to infringe the reputation and honor of heroes and martyrs and damage the public interest of society” can be jailed for up to three years.

The detentions underline Beijing’s sensitivity about the border clash with India – the deadliest between the two nuclear-armed neighbors in more than 40 years.

For eight months, the Chinese military did not disclose any details on the death toll of the bloody hand-to-hand conflict with Indian troops in the Galwan Valley area in the Himalayas. New Delhi previously said at least 20 Indian soldiers died during the brawl.

On Friday, China’s official army newspaper revealed that four People’s Liberation Army (PLA) soldiers were killed in the clash, and were given posthumous awards. A regimental commander who was seriously injured also received an award, according to the report.

In an ensuing propaganda campaign, Chinese state media outlets rushed to eulogize the five PLA soldiers for their loyalty, valor and sacrifice, publishing lengthy, emotive reports on their life stories.

State media also published Beijing’s account of the event, blaming Indian troops for violating an agreement with China and crossing the border into the Chinese side to set up tents. According to the PLA Daily, the Chinese side was at first outnumbered by Indian troops who attacked with steel tubes, clubs and rocks. But as PLA reinforcements arrived, they eventually “defeated” the Indian soldiers and chased them away.

The Indian military has not responded to CNN’s request for comment. Delhi has previously blamed Beijing for the skirmish.

However, not every Chinese citizen is convinced by Beijing’s account of the incident.

On Friday morning, a popular blogger with 2.5 million followers on China’s Twitter-like Weibo raised questions over the official death toll, suggesting the real figure might be higher than four. “This is why India dares to publicize the number and names of their casualties, because from India’s point of view, they won with a smaller cost,” he wrote.

By the evening, police in the eastern city of Nanjing had detained the blogger, identified by his surname Qiu, for “picking quarrels and provoking trouble” – an offense commonly used by the Chinese government to target dissent and criticism.

Writing on its official Weibo account Saturday, the Nanjing police claimed that Qiu had “distorted the truth” and “caused extremely abominable impact on society,” adding that he had confessed to his “unlawful act.”

Weibo said on Friday evening it had shut down Qiu’s account, which he used to post the remarks, as well as an additional account he owns.

According to police, four Weibo users in total were detained for their posts or comments on other people’s posts. Two others were detained for their comments in group chats on WeChat, China’s popular messaging app, after other group members reported them to the police. The other person was caught by the internet police in an “online patrol” after he posted on his personal WeChat feed.