ENGLISH Defence League protesters have been trying to invade Guildhall Square where an anti-fascism protest had been taking place.
Riot fans are blocking the entrance and dozens of officers are forming a wall to try and stop them from getting in.
However some protesters are trying to force their way through a barrier.
A short while ago, one protester climbed a tree at Guildhall Walk.
Mounted officers have now been called in and the road has been completely blocked off.
There are also protesters outside Portsmouth and Southsea train station.
Some protesters ran from Guildhall Walk area towards Greetham Street, closely followed by police where several of them approached a truck loaded with scaffolding poles.
However police managed to stop them from getting in.
Police are doing their best to contain the situation and seem to be keeping the protesters at bay.
Meanwhile traffic was blocked from the bottom of Commercial Road and Stanhope Road.