What's the role of the paramilitary policemen (PAP) vs. regular policemen in China?

I noticed this when I went to Beijing last February. When I was in Tiananmen Square, I noticed that paramilitary policemen was standing in attention (near the flag pole or at the entrance of the Great Hall of People). Whereas, the regular policemen (dark blue uniforms) were walking around the square. What is the role of the paramilitary policemen (wearing green uniform)? If both units have same roles wouldn't that be redundant on the PLA or the Central Military Commission? Just curious...

What's the role of the paramilitary policemen (PAP) vs. regular policemen in China?
The normal policemen are there for civil matters, the paramilitary police are there for matters of the state security, however the police can be ordered to back up the paramilitary police. As Tiananmen is the a government site you would find paramilitary police (or more likely soldiers) as well as normal police.





You will find guards around the flag in Tiananmen square as it is a symbol of the country its like why are there guards around the tomb of the unknown soldier in the USA.