After moving quickly to block reports in social media of a fiery — and deadly — car crash in Beijing's Tiananmen Square this week, Chinese police are now saying the incident was an act of "violent terrorism."

Authorities say the plot was "carefully planned, organized and premeditated," and that police have taken five suspects into custody in connection with the incident.

An SUV sped past barricades and slammed into a crowd of tourists at mid-day on Monday, injuring 38 people. Five people were killed, including two bystanders and the three who were inside the vehicle that caught fire.

The BBC has video of witnesses describing what they saw.

A statement from Beijing police identified the driver of the SUV as Usmen Hasan, accompanied in the car by his wife and his mother. It said gas, knives, iron rods and "extremist religious banners" were recovered from the vehicle, which had license plates registered in China's volatile western region of Xinjiang.

Xinjiang is home to some 10 million members of China's community of ethnic minority Uigurs, most of whom are Muslims. The Chinese government has long said that it faces a threat of violent extremism from Xinjiang. Members of the minority now fear an indiscriminate crackdown is already under way in response to the attack.