Forensic teams are working on sites across Britain in the investigation into the multi-million pound Securitas robbery.
Kent police said "a number" of search warrants had been executed, although the force refused to reveal if any further arrests had been made.
With police activity intensifying, armed officers apparently shot out the wheels of a car and arrested two men on a seafront road near Whitstable on the north Kent coast.
In Southborough, near Tunbridge Wells, forensic teams are searching a property following the £50 million armed raid on Saturday night.
Detectives believe that with the investigation into Britain's biggest robbery moving at such a fast pace, the robbers are making mistakes.
At a press conference yesterday, Kent Police Assistant Chief Constable Adrian Leppard said he remained "very confident" that the gang responsible for the raid would be caught.
He also revealed that the cash found in a white Transit van in an Ashford car park on Friday amounted to £1.3 million - "sizeably more" than originally thought. Forensic tests were being carried out on the guns, balaclavas and flak jackets also found in the back of the van, he added.
He revealed that 14 cages used by the gang to transport the huge cash haul had been dumped in fields near Maidstone at 9.30am on Wednesday, just hours after the raid.
Another appeal for information about the white Renault lorry used by the robbers was also issued. It was the only significant vehicle yet to be recovered.
Two men, aged 55 and 33, arrested on Saturday morning in the Maidstone area have now been released on police bail, along with a man (49) held later in the day.
Their release brings the total number of confirmed arrests in connection with the inquiry to six.