On the first Sunday of March, China awoke to sickening news: Black-clad attackers with knives had hacked through crowds at the train station in the southern city of Kunming, killing 29 and injuring more than 140.

Reporters leaped into action, gathering details from victims in their hospital beds. President Xi Jinping urged all-out efforts to investigate the slaughter. The incident was quickly dubbed “China’s 9/11.”

But by nightfall Monday, the state-run New China News Agency signaled that it was time to move on. “Kunming railway station serious violent terror case is successfully solved,” its headline said.

The public was left with just basic details, and since, there has been a deafening silence that has frustrated families of the victims. Analysts say China’s approach reflects a mix of embarrassment, self-interest and legitimate counter-terrorism strategy. At the same time, activist groups that normally would challenge authorities have their own reasons for not pushing for fuller disclosure.

… “This attack is a huge embarrassment to the Chinese,” said Rohan Gunaratna, a terrorism expert at Nanyang Technological University in Singapore. “Certainly this case is far from being resolved, because they have to track the money, the supporters, so many others who were involved. This kind of investigation will last easily more than a year. … No one should say that this case has been closed.”