The fiery car blaze at Tiananmen Square that killed five and injured dozens was a premeditated terrorist attack, Chinese police said on Wednesday after making five arrests in connection with the case.

The five suspects arrested, as well as the driver and two passengers that died in the blaze, were all identified with names that suggested they were ethnic Uighurs, a predominantly Muslim ethnic minority from China's restive far-western province of Xinjiang.

Police also found flags with jihadist and extremist religious messages, appearing to support early reports that the apparent suicide attack may have been a particularly audacious act of religious and political protest at the symbolic heart of the capital.

On Monday, a white four-wheel-drive veered off the road and onto a footpath, ploughing into crowds before bursting into flames in front of the main gate overlooking Tiananmen Square where the iconic portrait of Mao Zedong hangs.