Signs say there is a large police presence on the bridge, which was the scene of a monster attack earlier this year.
Half the bridge has been near off while Metropolitan Police attend the scene.
A police spokesman voiced officers were called at 6.45pm to reports of «someone threatening to spring».
Police remain at the scene but the spokesman added that the «road closure is due to be heave up exalted» as «the man just got into an ambulance».
One Twitter user said: «Lots of the Old Bill on Westminster Bridge and half the bridge closed, how worrying.
«Apparently there’s been some sort of upset at Elephant & Castle, perhaps it’s related.»
MORE TO FOLLOW….