China Tuesday released graphic video footage of the fiery car attack on Tiananmen Square that was blamed on militants from the restive Xinjiang region, as authorities act to stamp out growing unrest.

The images showed a white SUV entering the pavement before slamming into pedestrians at speed, sending some flying several feet into the air, before the vehicle came to a halt and burst into flames.

Some of those hit could be seen lying motionless on the floor, as scores of pedestrians darted from the on-rushing vehicle which had a black flag flying from a left window.

State media previously said a flag "bearing extremist religious references" was found after the attack.

All three people in the car -- a man, his wife and his mother -- died in the crash in Beijing's symbolic heart last October, while two tourists were also killed.

Three people were sentenced to death last week over the crash, while another was given life in prison for the "violent terrorist attack", state news agency Xinhua said.

Four other people were given prison terms ranging from five to 20 years, Xinhua said.

Less brutal images of the attack were shown by state broadcaster China Central Television (CCTV) in its reporting of the sentencing.

The new images were in a CCTV documentary that was screened Tuesday.

It was released in partnership with the State Internet Information Office, the Ministry of Public Security and the State Council, Xinhua said in a dispatch detailing the documentary's release.

The documentary also contained images of "terrorists" involved with the Tiananmen attack burning a Chinese flag as they shouted slogans.

None of the images could be verified by AFP.

Beijing has vowed a year-long crackdown on terrorism in recent weeks following several high-profile attacks blamed on Xinjiang militants, which since late last year struck outside the region and targeted ordinary citizens rather than government or security personnel.