Tourists trying to navigate major central London landmarks on Saturday were left bemused by an enormous £4.5m police operation to keep rival protestors apart.

Two major protests are under way in London amid a huge £4.5 million ($6 million) police operation.

The force was set to deploy 4,000 officers -- alongside horses, dogs, drones and helicopters -- to manage Robinson's so-called "Unite the Kingdom" march and the rival rally marking Nakba Day.