A gang has been arrested on suspicion of robbing people who were leaving London casinos.
The arrests came after officers carried out early morning raids at properties in Notting Hill, Harlesden and Palmers Green, in north and west London.
Officers believe a gang followed customers from casinos and then took their winnings.
Four men were arrested on suspicion of conspiracy to commit robbery and suspicion of money laundering.
One man was arrested in Ealing, west London, on suspicion of possessing a prohibited weapon.
Officers found CS spray while searching a property in Ealing.
Police said the gang was under investigation over three robberies last year - two on 2 September and the third on 1 October.