On Chinese social media, a picture of two Chinese female athletes accidentally made a reference to the Tiananmen Square massacre.
Lin Yuwei and Wu Yanni's race numbers add up to 64, which is a usual way to talk about what happened on June 4.
The event is still not allowed to be talked about in China, and any mention of it on the internet is often taken down by the government.
In Beijing in 1989, troops killed a lot of people who were protesting for freedom.
No one knows for sure how many people died that day, but human rights groups say that anywhere from a few hundred to a few thousand people died.
At the Asian Games, the players hugged each other after Ms. Lin won gold in the 100m hurdles race. In the picture, she wore lane number 6 next to Ms. Wu's lane number 4.
People had written nice things about Ms. Lin on Weibo, one of China's biggest social media sites. But dark squares were put in place of the photos in posts that had them.
But it doesn't look like the photo has been totally removed from the internet. Some Chinese news articles still have photos of the two athletes.
So far, China has won almost 300 medals at the Asian Games, which are taking place right now in Hangzhou, China. It will last until October 8.
At the Asian Games, the players hugged each other after Ms. Lin won gold in the 100m hurdles race. In the picture, she wore lane number 6 next to Ms. Wu's lane number 4.
People had written nice things about Ms. Lin on Weibo, one of China's biggest social media sites. But dark squares were put in place of the photos in posts that had them.
But it doesn't look like the photo has been totally removed from the internet. Some Chinese news articles still have photos of the two athletes.
So far, China has won almost 300 medals at the Asian Games, which are taking place right now in Hangzhou, China. It will last until October 8.