According to peddlers and policemen on Tiananmen Square, at around 7:00am on September 26, a bomb exploded at a recently built flower altar in the front of Tiananmen Square. Although the bomb was not very powerful, the police remained very nervous. It is said that some high-ranked central government officials planned to visit Tiananmen Square that day to see the new flower altar. Liu Qi, Mayor of Beijing and Ma Zhenchuan, Director of the Public Security Bureau of Beijing both went to Tiananmen Square to personally investigate the incident. The police carefully combed through the remains of the flower altar with sticks. Many flower pots were damaged, so more pots were later delivered to Tiananmen Square in order to fix the altar.
Tiananmen Square remained heavily guarded after the incident. A woman who came to Beijing to appeal at the Bureau of Letters and Visits said that police on the Square checked her bag twice. On September 26, 70 appealers were arrested. On September 27, a dozen policemen and many security guards in plain clothes searched for appealers. Almost 200 appealers were arrested in front of the Jinshui Bridge.
Around 10:30pm on the night of September 27, over 30 policemen and many public security guards suddenly surrounded the village at the Beijing South Train Station where over ten thousand appealers stay. The government sent more than twenty police cars, including three buses and five police vans specially made for large-scale arrests. The true number of arrests remains unclear.